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[NES] Switch to T65 CPU
This commit is contained in:
2
.gitignore
vendored
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2
.gitignore
vendored
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@@ -0,0 +1,2 @@
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out/
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PLLJ_PLLSPE_INFO.txt
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@@ -281,25 +281,29 @@ set_instance_assignment -name CURRENT_STRENGTH_NEW "MAXIMUM CURRENT" -to SDRAM_n
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set_instance_assignment -name CURRENT_STRENGTH_NEW "MAXIMUM CURRENT" -to SDRAM_nCS
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set_instance_assignment -name CURRENT_STRENGTH_NEW "MAXIMUM CURRENT" -to SDRAM_CKE
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set_instance_assignment -name CURRENT_STRENGTH_NEW "MAXIMUM CURRENT" -to SDRAM_CLK
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set_global_assignment -name SDC_FILE mist/constraints.sdc
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set_global_assignment -name VERILOG_FILE mist/ps2_intf.v
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set_global_assignment -name VERILOG_FILE mist/keyboard.v
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set_global_assignment -name VERILOG_FILE mist/sigma_delta_dac.v
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set_global_assignment -name VERILOG_FILE mist/data_io.v
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set_global_assignment -name VERILOG_FILE mist/sdram.v
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set_global_assignment -name VERILOG_FILE mist/user_io.v
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set_global_assignment -name VERILOG_FILE mist/osd.v
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set_global_assignment -name VERILOG_FILE mist/clk.v
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set_global_assignment -name VERILOG_FILE src/compat.v
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set_global_assignment -name VERILOG_FILE src/ppu.v
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set_global_assignment -name VERILOG_FILE src/mmu.v
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set_global_assignment -name VERILOG_FILE src/cpu.v
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set_global_assignment -name SYSTEMVERILOG_FILE src/video_mixer.sv
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set_global_assignment -name VERILOG_FILE src/video.v
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set_global_assignment -name VERILOG_FILE src/nes.v
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set_global_assignment -name VERILOG_FILE src/MicroCode.v
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set_global_assignment -name VERILOG_FILE src/hq2x.v
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set_global_assignment -name VERILOG_FILE src/dsp.v
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set_global_assignment -name VERILOG_FILE src/apu.v
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set_global_assignment -name VERILOG_FILE mist/NES_mist.v
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set_global_assignment -name VHDL_FILE t65/T65_Pack.vhd
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set_global_assignment -name VHDL_FILE t65/T65_MCode.vhd
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set_global_assignment -name VHDL_FILE t65/T65_ALU.vhd
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set_global_assignment -name VHDL_FILE t65/T65.vhd
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set_global_assignment -name QIP_FILE t65/t65.qip
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set_global_assignment -name SDC_FILE mist/constraints.sdc
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set_global_assignment -name VERILOG_FILE mist/ps2_intf.v
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set_global_assignment -name VERILOG_FILE mist/keyboard.v
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set_global_assignment -name VERILOG_FILE mist/sigma_delta_dac.v
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set_global_assignment -name VERILOG_FILE mist/data_io.v
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set_global_assignment -name VERILOG_FILE mist/sdram.v
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set_global_assignment -name VERILOG_FILE mist/user_io.v
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set_global_assignment -name VERILOG_FILE mist/osd.v
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set_global_assignment -name VERILOG_FILE mist/clk.v
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set_global_assignment -name VERILOG_FILE src/compat.v
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set_global_assignment -name VERILOG_FILE src/ppu.v
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set_global_assignment -name VERILOG_FILE src/mmu.v
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set_global_assignment -name SYSTEMVERILOG_FILE src/video_mixer.sv
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set_global_assignment -name VERILOG_FILE src/video.v
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set_global_assignment -name VERILOG_FILE src/nes.v
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set_global_assignment -name VERILOG_FILE src/MicroCode.v
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set_global_assignment -name VERILOG_FILE src/hq2x.v
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set_global_assignment -name VERILOG_FILE src/dsp.v
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set_global_assignment -name VERILOG_FILE src/apu.v
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set_global_assignment -name VERILOG_FILE mist/NES_mist.v
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set_instance_assignment -name PARTITION_HIERARCHY root_partition -to | -section_id Top
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@@ -178,12 +178,27 @@ module NES(input clk, input reset, input ce,
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// -- CPU
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wire [15:0] cpu_addr;
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wire cpu_mr, cpu_mw;
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wire cpu_rnw;
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wire pause_cpu;
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reg apu_irq_delayed;
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reg mapper_irq_delayed;
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CPU cpu(clk, apu_ce && !pause_cpu, reset, from_data_bus, apu_irq_delayed | mapper_irq_delayed, nmi_active, cpu_dout, cpu_addr, cpu_mr, cpu_mw);
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T65 cpu
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(
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.mode(0),
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.BCD_en(0),
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.res_n(~reset),
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.clk(clk),
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.enable(apu_ce && !pause_cpu),
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.IRQ_n(~(apu_irq_delayed | mapper_irq_delayed)),
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.NMI_n(~nmi_active),
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.R_W_n(cpu_rnw),
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.A(cpu_addr),
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.DI(cpu_rnw ? from_data_bus : cpu_dout),
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.DO(cpu_dout)
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);
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// -- DMA
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wire [15:0] dma_aout;
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wire dma_aout_enable;
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@@ -195,14 +210,14 @@ module NES(input clk, input reset, input ce,
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// Determine the values on the bus outgoing from the CPU chip (after DMA / APU)
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wire [15:0] addr = dma_aout_enable ? dma_aout : cpu_addr;
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wire [7:0] dbus = dma_aout_enable ? dma_data_to_ram : cpu_dout;
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wire mr_int = dma_aout_enable ? dma_read : cpu_mr;
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wire mw_int = dma_aout_enable ? !dma_read : cpu_mw;
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wire mr_int = dma_aout_enable ? dma_read : cpu_rnw;
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wire mw_int = dma_aout_enable ? !dma_read : !cpu_rnw;
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DmaController dma(clk, apu_ce, reset,
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odd_or_even, // Even or odd cycle
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(addr == 'h4014 && mw_int), // Sprite trigger
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apu_dma_request, // DMC Trigger
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cpu_mr, // CPU in a read cycle?
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cpu_rnw, // CPU in a read cycle?
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cpu_dout, // Data from cpu
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from_data_bus, // Data from RAM etc.
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apu_dma_addr, // DMC addr
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@@ -289,7 +304,7 @@ module NES(input clk, input reset, input ce,
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always @* begin
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if (reset)
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from_data_bus <= 0;
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from_data_bus = 0;
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else if (apu_cs) begin
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if (joypad1_cs)
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from_data_bus = {7'b0100000, joypad_data[0]};
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679
cores/nes/t65/T65.vhd
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679
cores/nes/t65/T65.vhd
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@@ -0,0 +1,679 @@
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-- ****
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-- T65(b) core. In an effort to merge and maintain bug fixes ....
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--
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-- Ver 313 WoS January 2015
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-- Fixed issue that NMI has to be first if issued the same time as a BRK instruction is latched in
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-- Now all Lorenz CPU tests on FPGAARCADE C64 core (sources used: SVN version 1021) are OK! :D :D :D
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-- This is just a starting point to go for optimizations and detailed fixes (the Lorenz test can't find)
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--
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-- Ver 312 WoS January 2015
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-- Undoc opcode timing fixes for $B3 (LAX iy) and $BB (LAS ay)
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-- Added comments in MCode section to find handling of individual opcodes more easily
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-- All "basic" Lorenz instruction test (individual functional checks, CPUTIMING check) work now with
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-- actual FPGAARCADE C64 core (sources used: SVN version 1021).
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--
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-- Ver 305, 306, 307, 308, 309, 310, 311 WoS January 2015
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-- Undoc opcode fixes (now all Lorenz test on instruction functionality working, except timing issues on $B3 and $BB):
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-- SAX opcode
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-- SHA opcode
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-- SHX opcode
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-- SHY opcode
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-- SHS opcode
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-- LAS opcode
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-- alternate SBC opcode
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-- fixed NOP with immediate param (caused Lorenz trap test to fail)
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-- IRQ and NMI timing fixes (in conjuction with branches)
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--
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-- Ver 304 WoS December 2014
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-- Undoc opcode fixes:
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-- ARR opcode
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-- ANE/XAA opcode
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-- Corrected issue with NMI/IRQ prio (when asserted the same time)
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--
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-- Ver 303 ost(ML) July 2014
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-- (Sorry for some scratchpad comments that may make little sense)
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-- Mods and some 6502 undocumented instructions.
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-- Not correct opcodes acc. to Lorenz tests (incomplete list):
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-- NOPN (nop)
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-- NOPZX (nop + byte 172)
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-- NOPAX (nop + word da ... da: byte 0)
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-- ASOZ (byte $07 + byte 172)
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--
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-- Ver 303,302 WoS April 2014
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-- Bugfixes for NMI from foft
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-- Bugfix for BRK command (and its special flag)
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--
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-- Ver 300,301 WoS January 2014
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-- More merging
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-- Bugfixes by ehenciak added, started tidyup *bust*
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--
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-- MikeJ March 2005
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-- Latest version from www.fpgaarcade.com (original www.opencores.org)
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-- ****
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--
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-- 65xx compatible microprocessor core
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--
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-- FPGAARCADE SVN: $Id: T65.vhd 1347 2015-05-27 20:07:34Z wolfgang.scherr $
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--
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-- Copyright (c) 2002...2015
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-- Daniel Wallner (jesus <at> opencores <dot> org)
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-- Mike Johnson (mikej <at> fpgaarcade <dot> com)
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-- Wolfgang Scherr (WoS <at> pin4 <dot> at>
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-- Morten Leikvoll ()
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--
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-- All rights reserved
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--
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-- Redistribution and use in source and synthezised forms, with or without
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-- modification, are permitted provided that the following conditions are met:
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--
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-- Redistributions of source code must retain the above copyright notice,
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-- this list of conditions and the following disclaimer.
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--
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-- Redistributions in synthesized form must reproduce the above copyright
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-- notice, this list of conditions and the following disclaimer in the
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-- documentation and/or other materials provided with the distribution.
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--
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-- Neither the name of the author nor the names of other contributors may
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-- be used to endorse or promote products derived from this software without
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-- specific prior written permission.
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--
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-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
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-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
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-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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-- POSSIBILITY OF SUCH DAMAGE.
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--
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-- Please report bugs to the author(s), but before you do so, please
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-- make sure that this is not a derivative work and that
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-- you have the latest version of this file.
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--
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-- ----- IMPORTANT NOTES -----
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--
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-- Limitations:
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-- 65C02 and 65C816 modes are incomplete (and definitely untested after all 6502 undoc fixes)
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-- 65C02 supported : inc, dec, phx, plx, phy, ply
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-- 65D02 missing : bra, ora, lda, cmp, sbc, tsb*2, trb*2, stz*2, bit*2, wai, stp, jmp, bbr*8, bbs*8
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-- Some interface signals behave incorrect
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-- NMI interrupt handling not nice, needs further rework (to cycle-based encoding).
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--
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-- Usage:
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-- The enable signal allows clock gating / throttling without using the ready signal.
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-- Set it to constant '1' when using the Clk input as the CPU clock directly.
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--
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-- TAKE CARE you route the DO signal back to the DI signal while R_W_n='0',
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-- otherwise some undocumented opcodes won't work correctly.
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-- EXAMPLE:
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-- CPU : entity work.T65
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-- port map (
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-- R_W_n => cpu_rwn_s,
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-- [....all other ports....]
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-- DI => cpu_din_s,
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-- DO => cpu_dout_s
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-- );
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-- cpu_din_s <= cpu_dout_s when cpu_rwn_s='0' else
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-- [....other sources from peripherals and memories...]
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--
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-- ----- IMPORTANT NOTES -----
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--
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library IEEE;
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use IEEE.std_logic_1164.all;
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use IEEE.numeric_std.all;
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use work.T65_Pack.all;
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entity T65 is
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port(
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Mode : in std_logic_vector(1 downto 0); -- "00" => 6502, "01" => 65C02, "10" => 65C816
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BCD_en : in std_logic := '1'; -- '0' => 2A03/2A07, '1' => others
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Res_n : in std_logic;
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Clk : in std_logic;
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Enable : in std_logic := '1';
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A : out std_logic_vector(23 downto 0);
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DI : in std_logic_vector(7 downto 0);
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DO : out std_logic_vector(7 downto 0);
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Rdy : in std_logic := '1';
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Abort_n : in std_logic := '1';
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IRQ_n : in std_logic := '1';
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NMI_n : in std_logic := '1';
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SO_n : in std_logic := '1';
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R_W_n : out std_logic;
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Sync : out std_logic;
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EF : out std_logic;
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MF : out std_logic;
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XF : out std_logic;
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ML_n : out std_logic;
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VP_n : out std_logic;
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VDA : out std_logic;
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VPA : out std_logic;
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DEBUG : out T_t65_dbg;
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NMI_ack : out std_logic
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);
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end T65;
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architecture rtl of T65 is
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-- Registers
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signal ABC, X, Y : std_logic_vector(15 downto 0);
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signal P, AD, DL : std_logic_vector(7 downto 0) := x"00";
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signal PwithB : std_logic_vector(7 downto 0);--ML:New way to push P with correct B state to stack
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signal BAH : std_logic_vector(7 downto 0);
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signal BAL : std_logic_vector(8 downto 0);
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signal PBR : std_logic_vector(7 downto 0);
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signal DBR : std_logic_vector(7 downto 0);
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signal PC : unsigned(15 downto 0);
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signal S : unsigned(15 downto 0);
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signal EF_i : std_logic;
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signal MF_i : std_logic;
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signal XF_i : std_logic;
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signal IR : std_logic_vector(7 downto 0);
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signal MCycle : std_logic_vector(2 downto 0);
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signal Mode_r : std_logic_vector(1 downto 0);
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signal BCD_en_r : std_logic;
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signal ALU_Op_r : T_ALU_Op;
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signal Write_Data_r : T_Write_Data;
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signal Set_Addr_To_r : T_Set_Addr_To;
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signal PCAdder : unsigned(8 downto 0);
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signal RstCycle : std_logic;
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signal IRQCycle : std_logic;
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signal NMICycle : std_logic;
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signal SO_n_o : std_logic;
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signal IRQ_n_o : std_logic;
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signal NMI_n_o : std_logic;
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signal NMIAct : std_logic;
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signal Break : std_logic;
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-- ALU signals
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signal BusA : std_logic_vector(7 downto 0);
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signal BusA_r : std_logic_vector(7 downto 0);
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signal BusB : std_logic_vector(7 downto 0);
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signal BusB_r : std_logic_vector(7 downto 0);
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signal ALU_Q : std_logic_vector(7 downto 0);
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signal P_Out : std_logic_vector(7 downto 0);
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-- Micro code outputs
|
||||
signal LCycle : std_logic_vector(2 downto 0);
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signal ALU_Op : T_ALU_Op;
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signal Set_BusA_To : T_Set_BusA_To;
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signal Set_Addr_To : T_Set_Addr_To;
|
||||
signal Write_Data : T_Write_Data;
|
||||
signal Jump : std_logic_vector(1 downto 0);
|
||||
signal BAAdd : std_logic_vector(1 downto 0);
|
||||
signal BreakAtNA : std_logic;
|
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signal ADAdd : std_logic;
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signal AddY : std_logic;
|
||||
signal PCAdd : std_logic;
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||||
signal Inc_S : std_logic;
|
||||
signal Dec_S : std_logic;
|
||||
signal LDA : std_logic;
|
||||
signal LDP : std_logic;
|
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signal LDX : std_logic;
|
||||
signal LDY : std_logic;
|
||||
signal LDS : std_logic;
|
||||
signal LDDI : std_logic;
|
||||
signal LDALU : std_logic;
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||||
signal LDAD : std_logic;
|
||||
signal LDBAL : std_logic;
|
||||
signal LDBAH : std_logic;
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||||
signal SaveP : std_logic;
|
||||
signal Write : std_logic;
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||||
|
||||
signal Res_n_i : std_logic;
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||||
signal Res_n_d : std_logic;
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signal really_rdy : std_logic;
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signal WRn_i : std_logic;
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signal NMI_entered : std_logic;
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begin
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NMI_ack <= NMIAct;
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||||
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||||
-- gate Rdy with read/write to make an "OK, it's really OK to stop the processor
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||||
really_rdy <= Rdy or not(WRn_i);
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||||
Sync <= '1' when MCycle = "000" else '0';
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||||
EF <= EF_i;
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||||
MF <= MF_i;
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||||
XF <= XF_i;
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||||
R_W_n <= WRn_i;
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||||
ML_n <= '0' when IR(7 downto 6) /= "10" and IR(2 downto 1) = "11" and MCycle(2 downto 1) /= "00" else '1';
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||||
VP_n <= '0' when IRQCycle = '1' and (MCycle = "101" or MCycle = "110") else '1';
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||||
VDA <= '1' when Set_Addr_To_r /= Set_Addr_To_PBR else '0';
|
||||
VPA <= '1' when Jump(1) = '0' else '0';
|
||||
|
||||
-- debugging signals
|
||||
DEBUG.I <= IR;
|
||||
DEBUG.A <= ABC(7 downto 0);
|
||||
DEBUG.X <= X(7 downto 0);
|
||||
DEBUG.Y <= Y(7 downto 0);
|
||||
DEBUG.S <= std_logic_vector(S(7 downto 0));
|
||||
DEBUG.P <= P;
|
||||
|
||||
mcode : entity work.T65_MCode
|
||||
port map(
|
||||
--inputs
|
||||
Mode => Mode_r,
|
||||
IR => IR,
|
||||
MCycle => MCycle,
|
||||
P => P,
|
||||
--outputs
|
||||
LCycle => LCycle,
|
||||
ALU_Op => ALU_Op,
|
||||
Set_BusA_To => Set_BusA_To,
|
||||
Set_Addr_To => Set_Addr_To,
|
||||
Write_Data => Write_Data,
|
||||
Jump => Jump,
|
||||
BAAdd => BAAdd,
|
||||
BreakAtNA => BreakAtNA,
|
||||
ADAdd => ADAdd,
|
||||
AddY => AddY,
|
||||
PCAdd => PCAdd,
|
||||
Inc_S => Inc_S,
|
||||
Dec_S => Dec_S,
|
||||
LDA => LDA,
|
||||
LDP => LDP,
|
||||
LDX => LDX,
|
||||
LDY => LDY,
|
||||
LDS => LDS,
|
||||
LDDI => LDDI,
|
||||
LDALU => LDALU,
|
||||
LDAD => LDAD,
|
||||
LDBAL => LDBAL,
|
||||
LDBAH => LDBAH,
|
||||
SaveP => SaveP,
|
||||
Write => Write
|
||||
);
|
||||
|
||||
alu : entity work.T65_ALU
|
||||
port map(
|
||||
Mode => Mode_r,
|
||||
BCD_en => BCD_en_r,
|
||||
Op => ALU_Op_r,
|
||||
BusA => BusA_r,
|
||||
BusB => BusB,
|
||||
P_In => P,
|
||||
P_Out => P_Out,
|
||||
Q => ALU_Q
|
||||
);
|
||||
|
||||
-- the 65xx design requires at least two clock cycles before
|
||||
-- starting its reset sequence (according to datasheet)
|
||||
process (Res_n, Clk)
|
||||
begin
|
||||
if Res_n = '0' then
|
||||
Res_n_i <= '0';
|
||||
Res_n_d <= '0';
|
||||
elsif Clk'event and Clk = '1' then
|
||||
Res_n_i <= Res_n_d;
|
||||
Res_n_d <= '1';
|
||||
end if;
|
||||
end process;
|
||||
|
||||
process (Res_n_i, Clk)
|
||||
begin
|
||||
if Res_n_i = '0' then
|
||||
PC <= (others => '0'); -- Program Counter
|
||||
IR <= "00000000";
|
||||
S <= (others => '0'); -- Dummy
|
||||
PBR <= (others => '0');
|
||||
DBR <= (others => '0');
|
||||
|
||||
Mode_r <= (others => '0');
|
||||
BCD_en_r <= '1';
|
||||
ALU_Op_r <= ALU_OP_BIT;
|
||||
Write_Data_r <= Write_Data_DL;
|
||||
Set_Addr_To_r <= Set_Addr_To_PBR;
|
||||
|
||||
WRn_i <= '1';
|
||||
EF_i <= '1';
|
||||
MF_i <= '1';
|
||||
XF_i <= '1';
|
||||
|
||||
elsif Clk'event and Clk = '1' then
|
||||
if (Enable = '1') then
|
||||
if (really_rdy = '1') then
|
||||
WRn_i <= not Write or RstCycle;
|
||||
|
||||
PBR <= (others => '1'); -- Dummy
|
||||
DBR <= (others => '1'); -- Dummy
|
||||
EF_i <= '0'; -- Dummy
|
||||
MF_i <= '0'; -- Dummy
|
||||
XF_i <= '0'; -- Dummy
|
||||
|
||||
if MCycle = "000" then
|
||||
Mode_r <= Mode;
|
||||
BCD_en_r <= BCD_en;
|
||||
|
||||
if IRQCycle = '0' and NMICycle = '0' then
|
||||
PC <= PC + 1;
|
||||
end if;
|
||||
|
||||
if IRQCycle = '1' or NMICycle = '1' then
|
||||
IR <= "00000000";
|
||||
else
|
||||
IR <= DI;
|
||||
end if;
|
||||
|
||||
if LDS = '1' then -- LAS won't work properly if not limited to machine cycle 0
|
||||
S(7 downto 0) <= unsigned(ALU_Q);
|
||||
end if;
|
||||
end if;
|
||||
|
||||
ALU_Op_r <= ALU_Op;
|
||||
Write_Data_r <= Write_Data;
|
||||
if Break = '1' then
|
||||
Set_Addr_To_r <= Set_Addr_To_PBR;
|
||||
else
|
||||
Set_Addr_To_r <= Set_Addr_To;
|
||||
end if;
|
||||
|
||||
if Inc_S = '1' then
|
||||
S <= S + 1;
|
||||
end if;
|
||||
if Dec_S = '1' and (RstCycle = '0' or Mode="00") then -- 6502 only?
|
||||
S <= S - 1;
|
||||
end if;
|
||||
|
||||
if IR = "00000000" and MCycle = "001" and IRQCycle = '0' and NMICycle = '0' then
|
||||
PC <= PC + 1;
|
||||
end if;
|
||||
--
|
||||
-- jump control logic
|
||||
--
|
||||
case Jump is
|
||||
when "01" =>
|
||||
PC <= PC + 1;
|
||||
when "10" =>
|
||||
PC <= unsigned(DI & DL);
|
||||
when "11" =>
|
||||
if PCAdder(8) = '1' then
|
||||
if DL(7) = '0' then
|
||||
PC(15 downto 8) <= PC(15 downto 8) + 1;
|
||||
else
|
||||
PC(15 downto 8) <= PC(15 downto 8) - 1;
|
||||
end if;
|
||||
end if;
|
||||
PC(7 downto 0) <= PCAdder(7 downto 0);
|
||||
when others => null;
|
||||
end case;
|
||||
end if;
|
||||
end if;
|
||||
end if;
|
||||
end process;
|
||||
|
||||
PCAdder <= resize(PC(7 downto 0),9) + resize(unsigned(DL(7) & DL),9) when PCAdd = '1'
|
||||
else "0" & PC(7 downto 0);
|
||||
|
||||
process (Res_n_i, Clk)
|
||||
variable tmpP:std_logic_vector(7 downto 0);--Lets try to handle loading P at mcycle=0 and set/clk flags at same cycle
|
||||
begin
|
||||
if Res_n_i = '0' then
|
||||
P <= x"00"; -- ensure we have nothing set on reset
|
||||
elsif Clk'event and Clk = '1' then
|
||||
tmpP:=P;
|
||||
if (Enable = '1') then
|
||||
if (really_rdy = '1') then
|
||||
if MCycle = "000" then
|
||||
if LDA = '1' then
|
||||
ABC(7 downto 0) <= ALU_Q;
|
||||
end if;
|
||||
if LDX = '1' then
|
||||
X(7 downto 0) <= ALU_Q;
|
||||
end if;
|
||||
if LDY = '1' then
|
||||
Y(7 downto 0) <= ALU_Q;
|
||||
end if;
|
||||
if (LDA or LDX or LDY) = '1' then
|
||||
tmpP:=P_Out;
|
||||
end if;
|
||||
end if;
|
||||
if SaveP = '1' then
|
||||
tmpP:=P_Out;
|
||||
end if;
|
||||
if LDP = '1' then
|
||||
tmpP:=ALU_Q;
|
||||
end if;
|
||||
if IR(4 downto 0) = "11000" then
|
||||
case IR(7 downto 5) is
|
||||
when "000" =>--0x18(clc)
|
||||
tmpP(Flag_C) := '0';
|
||||
when "001" =>--0x38(sec)
|
||||
tmpP(Flag_C) := '1';
|
||||
when "010" =>--0x58(cli)
|
||||
tmpP(Flag_I) := '0';
|
||||
when "011" =>--0x78(sei)
|
||||
tmpP(Flag_I) := '1';
|
||||
when "101" =>--0xb8(clv)
|
||||
tmpP(Flag_V) := '0';
|
||||
when "110" =>--0xd8(cld)
|
||||
tmpP(Flag_D) := '0';
|
||||
when "111" =>--0xf8(sed)
|
||||
tmpP(Flag_D) := '1';
|
||||
when others =>
|
||||
end case;
|
||||
end if;
|
||||
tmpP(Flag_B) := '1';
|
||||
if IR = "00000000" and MCycle = "100" and RstCycle = '0' then
|
||||
--This should happen after P has been pushed to stack
|
||||
tmpP(Flag_I) := '1';
|
||||
end if;
|
||||
if RstCycle = '1' then
|
||||
tmpP(Flag_I) := '1';
|
||||
tmpP(Flag_D) := '0';
|
||||
end if;
|
||||
tmpP(Flag_1) := '1';
|
||||
|
||||
P<=tmpP;--new way
|
||||
|
||||
if IR(4 downto 0)/="10000" or Jump/="01" then -- delay interrupts during branches (checked with Lorenz test and real 6510), not best way yet, though - but works...
|
||||
IRQ_n_o <= IRQ_n;
|
||||
end if;
|
||||
end if;
|
||||
-- detect nmi even if not rdy
|
||||
if IR(4 downto 0)/="10000" or Jump/="01" then -- delay interrupts during branches (checked with Lorenz test and real 6510) not best way yet, though - but works...
|
||||
NMI_n_o <= NMI_n;
|
||||
end if;
|
||||
end if;
|
||||
-- act immediately on SO pin change
|
||||
-- The signal is sampled on the trailing edge of phi1 and must be externally synchronized (from datasheet)
|
||||
SO_n_o <= SO_n;
|
||||
if SO_n_o = '1' and SO_n = '0' then
|
||||
P(Flag_V) <= '1';
|
||||
end if;
|
||||
|
||||
end if;
|
||||
end process;
|
||||
|
||||
---------------------------------------------------------------------------
|
||||
--
|
||||
-- Buses
|
||||
--
|
||||
---------------------------------------------------------------------------
|
||||
|
||||
process (Res_n_i, Clk)
|
||||
begin
|
||||
if Res_n_i = '0' then
|
||||
BusA_r <= (others => '0');
|
||||
BusB <= (others => '0');
|
||||
BusB_r <= (others => '0');
|
||||
AD <= (others => '0');
|
||||
BAL <= (others => '0');
|
||||
BAH <= (others => '0');
|
||||
DL <= (others => '0');
|
||||
elsif Clk'event and Clk = '1' then
|
||||
if (Enable = '1') then
|
||||
NMI_entered <= '0';
|
||||
if (really_rdy = '1') then
|
||||
BusA_r <= BusA;
|
||||
BusB <= DI;
|
||||
|
||||
-- not really nice, but no better way found yet !
|
||||
if Set_Addr_To_r = Set_Addr_To_PBR or Set_Addr_To_r = Set_Addr_To_ZPG then
|
||||
BusB_r <= std_logic_vector(unsigned(DI(7 downto 0)) + 1); -- required for SHA
|
||||
end if;
|
||||
|
||||
case BAAdd is
|
||||
when "01" =>
|
||||
-- BA Inc
|
||||
AD <= std_logic_vector(unsigned(AD) + 1);
|
||||
BAL <= std_logic_vector(unsigned(BAL) + 1);
|
||||
when "10" =>
|
||||
-- BA Add
|
||||
BAL <= std_logic_vector(resize(unsigned(BAL(7 downto 0)),9) + resize(unsigned(BusA),9));
|
||||
when "11" =>
|
||||
-- BA Adj
|
||||
if BAL(8) = '1' then
|
||||
BAH <= std_logic_vector(unsigned(BAH) + 1);
|
||||
end if;
|
||||
when others =>
|
||||
end case;
|
||||
|
||||
-- modified to use Y register as well
|
||||
if ADAdd = '1' then
|
||||
if (AddY = '1') then
|
||||
AD <= std_logic_vector(unsigned(AD) + unsigned(Y(7 downto 0)));
|
||||
else
|
||||
AD <= std_logic_vector(unsigned(AD) + unsigned(X(7 downto 0)));
|
||||
end if;
|
||||
end if;
|
||||
|
||||
if IR = "00000000" then
|
||||
BAL <= (others => '1');
|
||||
BAH <= (others => '1');
|
||||
if RstCycle = '1' then
|
||||
BAL(2 downto 0) <= "100";
|
||||
elsif NMICycle = '1' or (NMIAct = '1' and MCycle="100") or NMI_entered='1' then
|
||||
BAL(2 downto 0) <= "010";
|
||||
if MCycle="100" then
|
||||
NMI_entered <= '1';
|
||||
end if;
|
||||
else
|
||||
BAL(2 downto 0) <= "110";
|
||||
end if;
|
||||
if Set_addr_To_r = Set_Addr_To_BA then
|
||||
BAL(0) <= '1';
|
||||
end if;
|
||||
end if;
|
||||
|
||||
if LDDI = '1' then
|
||||
DL <= DI;
|
||||
end if;
|
||||
if LDALU = '1' then
|
||||
DL <= ALU_Q;
|
||||
end if;
|
||||
if LDAD = '1' then
|
||||
AD <= DI;
|
||||
end if;
|
||||
if LDBAL = '1' then
|
||||
BAL(7 downto 0) <= DI;
|
||||
end if;
|
||||
if LDBAH = '1' then
|
||||
BAH <= DI;
|
||||
end if;
|
||||
end if;
|
||||
end if;
|
||||
end if;
|
||||
end process;
|
||||
|
||||
Break <= (BreakAtNA and not BAL(8)) or (PCAdd and not PCAdder(8));
|
||||
|
||||
with Set_BusA_To select
|
||||
BusA <=
|
||||
DI when Set_BusA_To_DI,
|
||||
ABC(7 downto 0) when Set_BusA_To_ABC,
|
||||
X(7 downto 0) when Set_BusA_To_X,
|
||||
Y(7 downto 0) when Set_BusA_To_Y,
|
||||
std_logic_vector(S(7 downto 0)) when Set_BusA_To_S,
|
||||
P when Set_BusA_To_P,
|
||||
ABC(7 downto 0) and DI when Set_BusA_To_DA,
|
||||
(ABC(7 downto 0) or x"ee") and DI when Set_BusA_To_DAO,--ee for OAL instruction. constant may be different on other platforms.TODO:Move to generics
|
||||
(ABC(7 downto 0) or x"ee") and DI and X(7 downto 0) when Set_BusA_To_DAX,--XAA, ee for OAL instruction. constant may be different on other platforms.TODO:Move to generics
|
||||
ABC(7 downto 0) and X(7 downto 0) when Set_BusA_To_AAX,--SAX, SHA
|
||||
(others => '-') when Set_BusA_To_DONTCARE;--Can probably remove this
|
||||
|
||||
with Set_Addr_To_r select
|
||||
A <=
|
||||
"0000000000000001" & std_logic_vector(S(7 downto 0)) when Set_Addr_To_SP,
|
||||
DBR & "00000000" & AD when Set_Addr_To_ZPG,
|
||||
"00000000" & BAH & BAL(7 downto 0) when Set_Addr_To_BA,
|
||||
PBR & std_logic_vector(PC(15 downto 8)) & std_logic_vector(PCAdder(7 downto 0)) when Set_Addr_To_PBR;
|
||||
|
||||
-- This is the P that gets pushed on stack with correct B flag. I'm not sure if NMI also clears B, but I guess it does.
|
||||
PwithB<=(P and x"ef") when (IRQCycle='1' or NMICycle='1') else P;
|
||||
|
||||
with Write_Data_r select
|
||||
DO <=
|
||||
DL when Write_Data_DL,
|
||||
ABC(7 downto 0) when Write_Data_ABC,
|
||||
X(7 downto 0) when Write_Data_X,
|
||||
Y(7 downto 0) when Write_Data_Y,
|
||||
std_logic_vector(S(7 downto 0)) when Write_Data_S,
|
||||
PwithB when Write_Data_P,
|
||||
std_logic_vector(PC(7 downto 0)) when Write_Data_PCL,
|
||||
std_logic_vector(PC(15 downto 8)) when Write_Data_PCH,
|
||||
ABC(7 downto 0) and X(7 downto 0) when Write_Data_AX,
|
||||
ABC(7 downto 0) and X(7 downto 0) and BusB_r(7 downto 0) when Write_Data_AXB, -- no better way found yet...
|
||||
X(7 downto 0) and BusB_r(7 downto 0) when Write_Data_XB, -- no better way found yet...
|
||||
Y(7 downto 0) and BusB_r(7 downto 0) when Write_Data_YB, -- no better way found yet...
|
||||
(others=>'-') when Write_Data_DONTCARE;--Can probably remove this
|
||||
|
||||
|
||||
-------------------------------------------------------------------------
|
||||
--
|
||||
-- Main state machine
|
||||
--
|
||||
-------------------------------------------------------------------------
|
||||
|
||||
process (Res_n_i, Clk)
|
||||
begin
|
||||
if Res_n_i = '0' then
|
||||
MCycle <= "001";
|
||||
RstCycle <= '1';
|
||||
IRQCycle <= '0';
|
||||
NMICycle <= '0';
|
||||
NMIAct <= '0';
|
||||
elsif Clk'event and Clk = '1' then
|
||||
if (Enable = '1') then
|
||||
if (really_rdy = '1') then
|
||||
if MCycle = LCycle or Break = '1' then
|
||||
MCycle <= "000";
|
||||
RstCycle <= '0';
|
||||
IRQCycle <= '0';
|
||||
NMICycle <= '0';
|
||||
if NMIAct = '1' and IR/=x"00" then -- delay NMI further if we just executed a BRK
|
||||
NMICycle <= '1';
|
||||
NMIAct <= '0'; -- reset NMI edge detector if we start processing the NMI
|
||||
elsif IRQ_n_o = '0' and P(Flag_I) = '0' then
|
||||
IRQCycle <= '1';
|
||||
end if;
|
||||
else
|
||||
MCycle <= std_logic_vector(unsigned(MCycle) + 1);
|
||||
end if;
|
||||
end if;
|
||||
--detect NMI even if not rdy
|
||||
if NMI_n_o = '1' and (NMI_n = '0' and (IR(4 downto 0)/="10000" or Jump/="01")) then -- branches have influence on NMI start (not best way yet, though - but works...)
|
||||
NMIAct <= '1';
|
||||
end if;
|
||||
-- we entered NMI during BRK instruction
|
||||
if NMI_entered='1' then
|
||||
NMIAct <= '0';
|
||||
end if;
|
||||
end if;
|
||||
end if;
|
||||
end process;
|
||||
|
||||
end;
|
||||
294
cores/nes/t65/T65_ALU.vhd
Normal file
294
cores/nes/t65/T65_ALU.vhd
Normal file
@@ -0,0 +1,294 @@
|
||||
-- ****
|
||||
-- T65(b) core. In an effort to merge and maintain bug fixes ....
|
||||
--
|
||||
-- See list of changes in T65 top file (T65.vhd)...
|
||||
--
|
||||
-- ****
|
||||
-- 65xx compatible microprocessor core
|
||||
--
|
||||
-- FPGAARCADE SVN: $Id: T65_ALU.vhd 1234 2015-02-28 20:14:50Z wolfgang.scherr $
|
||||
--
|
||||
-- Copyright (c) 2002...2015
|
||||
-- Daniel Wallner (jesus <at> opencores <dot> org)
|
||||
-- Mike Johnson (mikej <at> fpgaarcade <dot> com)
|
||||
-- Wolfgang Scherr (WoS <at> pin4 <dot> at>
|
||||
-- Morten Leikvoll ()
|
||||
--
|
||||
-- All rights reserved
|
||||
--
|
||||
-- Redistribution and use in source and synthezised forms, with or without
|
||||
-- modification, are permitted provided that the following conditions are met:
|
||||
--
|
||||
-- Redistributions of source code must retain the above copyright notice,
|
||||
-- this list of conditions and the following disclaimer.
|
||||
--
|
||||
-- Redistributions in synthesized form must reproduce the above copyright
|
||||
-- notice, this list of conditions and the following disclaimer in the
|
||||
-- documentation and/or other materials provided with the distribution.
|
||||
--
|
||||
-- Neither the name of the author nor the names of other contributors may
|
||||
-- be used to endorse or promote products derived from this software without
|
||||
-- specific prior written permission.
|
||||
--
|
||||
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||||
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
||||
-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||||
-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
|
||||
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||||
-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
||||
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||||
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
||||
-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||||
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
-- POSSIBILITY OF SUCH DAMAGE.
|
||||
--
|
||||
-- Please report bugs to the author(s), but before you do so, please
|
||||
-- make sure that this is not a derivative work and that
|
||||
-- you have the latest version of this file.
|
||||
--
|
||||
-- Limitations :
|
||||
-- See in T65 top file (T65.vhd)...
|
||||
|
||||
library IEEE;
|
||||
use IEEE.std_logic_1164.all;
|
||||
use IEEE.numeric_std.all;
|
||||
use work.T65_Pack.all;
|
||||
|
||||
entity T65_ALU is
|
||||
port(
|
||||
Mode : in std_logic_vector(1 downto 0); -- "00" => 6502, "01" => 65C02, "10" => 65816
|
||||
BCD_en : in std_logic;
|
||||
Op : in T_ALU_OP;
|
||||
BusA : in std_logic_vector(7 downto 0);
|
||||
BusB : in std_logic_vector(7 downto 0);
|
||||
P_In : in std_logic_vector(7 downto 0);
|
||||
P_Out : out std_logic_vector(7 downto 0);
|
||||
Q : out std_logic_vector(7 downto 0)
|
||||
);
|
||||
end T65_ALU;
|
||||
|
||||
architecture rtl of T65_ALU is
|
||||
|
||||
-- AddSub variables (temporary signals)
|
||||
signal ADC_Z : std_logic;
|
||||
signal ADC_C : std_logic;
|
||||
signal ADC_V : std_logic;
|
||||
signal ADC_N : std_logic;
|
||||
signal ADC_Q : std_logic_vector(7 downto 0);
|
||||
signal SBC_Z : std_logic;
|
||||
signal SBC_C : std_logic;
|
||||
signal SBC_V : std_logic;
|
||||
signal SBC_N : std_logic;
|
||||
signal SBC_Q : std_logic_vector(7 downto 0);
|
||||
signal SBX_Q : std_logic_vector(7 downto 0);
|
||||
|
||||
begin
|
||||
|
||||
process (P_In, BusA, BusB, BCD_en)
|
||||
variable AL : unsigned(6 downto 0);
|
||||
variable AH : unsigned(6 downto 0);
|
||||
variable C : std_logic;
|
||||
begin
|
||||
AL := resize(unsigned(BusA(3 downto 0) & P_In(Flag_C)), 7) + resize(unsigned(BusB(3 downto 0) & "1"), 7);
|
||||
AH := resize(unsigned(BusA(7 downto 4) & AL(5)), 7) + resize(unsigned(BusB(7 downto 4) & "1"), 7);
|
||||
|
||||
-- pragma translate_off
|
||||
if is_x(std_logic_vector(AL)) then AL := "0000000"; end if;
|
||||
if is_x(std_logic_vector(AH)) then AH := "0000000"; end if;
|
||||
-- pragma translate_on
|
||||
|
||||
if AL(4 downto 1) = 0 and AH(4 downto 1) = 0 then
|
||||
ADC_Z <= '1';
|
||||
else
|
||||
ADC_Z <= '0';
|
||||
end if;
|
||||
|
||||
if AL(5 downto 1) > 9 and P_In(Flag_D) = '1' and BCD_en = '1' then
|
||||
AL(6 downto 1) := AL(6 downto 1) + 6;
|
||||
end if;
|
||||
|
||||
C := AL(6) or AL(5);
|
||||
AH := resize(unsigned(BusA(7 downto 4) & C), 7) + resize(unsigned(BusB(7 downto 4) & "1"), 7);
|
||||
|
||||
ADC_N <= AH(4);
|
||||
ADC_V <= (AH(4) xor BusA(7)) and not (BusA(7) xor BusB(7));
|
||||
|
||||
-- pragma translate_off
|
||||
if is_x(std_logic_vector(AH)) then AH := "0000000"; end if;
|
||||
-- pragma translate_on
|
||||
|
||||
if AH(5 downto 1) > 9 and P_In(Flag_D) = '1' and BCD_en = '1' then
|
||||
AH(6 downto 1) := AH(6 downto 1) + 6;
|
||||
end if;
|
||||
|
||||
ADC_C <= AH(6) or AH(5);
|
||||
|
||||
ADC_Q <= std_logic_vector(AH(4 downto 1) & AL(4 downto 1));
|
||||
end process;
|
||||
|
||||
process (Op, P_In, BusA, BusB, BCD_en)
|
||||
variable AL : unsigned(6 downto 0);
|
||||
variable AH : unsigned(5 downto 0);
|
||||
variable C : std_logic;
|
||||
variable CT : std_logic;
|
||||
begin
|
||||
CT:='0';
|
||||
if( Op=ALU_OP_AND or --"0001" These OpCodes used to have LSB set
|
||||
Op=ALU_OP_ADC or --"0011"
|
||||
Op=ALU_OP_EQ2 or --"0101"
|
||||
Op=ALU_OP_SBC or --"0111"
|
||||
Op=ALU_OP_ROL or --"1001"
|
||||
Op=ALU_OP_ROR or --"1011"
|
||||
-- Op=ALU_OP_EQ3 or --"1101"
|
||||
Op=ALU_OP_INC --"1111"
|
||||
) then
|
||||
CT:='1';
|
||||
end if;
|
||||
|
||||
C := P_In(Flag_C) or not CT;--was: or not Op(0);
|
||||
AL := resize(unsigned(BusA(3 downto 0) & C), 7) - resize(unsigned(BusB(3 downto 0) & "1"), 6);
|
||||
AH := resize(unsigned(BusA(7 downto 4) & "0"), 6) - resize(unsigned(BusB(7 downto 4) & AL(5)), 6);
|
||||
|
||||
-- pragma translate_off
|
||||
if is_x(std_logic_vector(AL)) then AL := "0000000"; end if;
|
||||
if is_x(std_logic_vector(AH)) then AH := "000000"; end if;
|
||||
-- pragma translate_on
|
||||
|
||||
if AL(4 downto 1) = 0 and AH(4 downto 1) = 0 then
|
||||
SBC_Z <= '1';
|
||||
else
|
||||
SBC_Z <= '0';
|
||||
end if;
|
||||
|
||||
SBC_C <= not AH(5);
|
||||
SBC_V <= (AH(4) xor BusA(7)) and (BusA(7) xor BusB(7));
|
||||
SBC_N <= AH(4);
|
||||
|
||||
SBX_Q <= std_logic_vector(AH(4 downto 1) & AL(4 downto 1));
|
||||
|
||||
if P_In(Flag_D) = '1' and BCD_en = '1' then
|
||||
if AL(5) = '1' then
|
||||
AL(5 downto 1) := AL(5 downto 1) - 6;
|
||||
end if;
|
||||
AH := resize(unsigned(BusA(7 downto 4) & "0"), 6) - resize(unsigned(BusB(7 downto 4) & AL(6)), 6);
|
||||
if AH(5) = '1' then
|
||||
AH(5 downto 1) := AH(5 downto 1) - 6;
|
||||
end if;
|
||||
end if;
|
||||
|
||||
SBC_Q <= std_logic_vector(AH(4 downto 1) & AL(4 downto 1));
|
||||
end process;
|
||||
|
||||
process (Op, P_In, BusA, BusB,
|
||||
ADC_Z, ADC_C, ADC_V, ADC_N, ADC_Q,
|
||||
SBC_Z, SBC_C, SBC_V, SBC_N, SBC_Q,
|
||||
SBX_Q, BCD_en)
|
||||
variable Q_t : std_logic_vector(7 downto 0);
|
||||
variable Q2_t : std_logic_vector(7 downto 0);
|
||||
begin
|
||||
-- ORA, AND, EOR, ADC, NOP, LD, CMP, SBC
|
||||
-- ASL, ROL, LSR, ROR, BIT, LD, DEC, INC
|
||||
P_Out <= P_In;
|
||||
Q_t := BusA;
|
||||
Q2_t := Q_t;
|
||||
case Op is
|
||||
when ALU_OP_OR=>
|
||||
Q_t := BusA or BusB;
|
||||
when ALU_OP_AND=>
|
||||
Q_t := BusA and BusB;
|
||||
when ALU_OP_EOR=>
|
||||
Q_t := BusA xor BusB;
|
||||
when ALU_OP_ADC=>
|
||||
P_Out(Flag_V) <= ADC_V;
|
||||
P_Out(Flag_C) <= ADC_C;
|
||||
Q_t := ADC_Q;
|
||||
when ALU_OP_CMP=>
|
||||
P_Out(Flag_C) <= SBC_C;
|
||||
when ALU_OP_SAX=>
|
||||
P_Out(Flag_C) <= SBC_C;
|
||||
Q_t := SBX_Q; -- undoc: subtract (A & X) - (immediate)
|
||||
when ALU_OP_SBC=>
|
||||
P_Out(Flag_V) <= SBC_V;
|
||||
P_Out(Flag_C) <= SBC_C;
|
||||
Q_t := SBC_Q; -- undoc: subtract (A & X) - (immediate), then decimal correction
|
||||
when ALU_OP_ASL=>
|
||||
Q_t := BusA(6 downto 0) & "0";
|
||||
P_Out(Flag_C) <= BusA(7);
|
||||
when ALU_OP_ROL=>
|
||||
Q_t := BusA(6 downto 0) & P_In(Flag_C);
|
||||
P_Out(Flag_C) <= BusA(7);
|
||||
when ALU_OP_LSR=>
|
||||
Q_t := "0" & BusA(7 downto 1);
|
||||
P_Out(Flag_C) <= BusA(0);
|
||||
when ALU_OP_ROR=>
|
||||
Q_t := P_In(Flag_C) & BusA(7 downto 1);
|
||||
P_Out(Flag_C) <= BusA(0);
|
||||
when ALU_OP_ARR=>
|
||||
Q_t := P_In(Flag_C) & (BusA(7 downto 1) and BusB(7 downto 1));
|
||||
P_Out(Flag_V) <= Q_t(5) xor Q_t(6);
|
||||
Q2_t := Q_t;
|
||||
if P_In(Flag_D)='1' and BCD_en = '1' then
|
||||
if (BusA(3 downto 0) and BusB(3 downto 0)) > "0100" then
|
||||
Q2_t(3 downto 0) := std_logic_vector(unsigned(Q_t(3 downto 0)) + x"6");
|
||||
end if;
|
||||
if (BusA(7 downto 4) and BusB(7 downto 4)) > "0100" then
|
||||
Q2_t(7 downto 4) := std_logic_vector(unsigned(Q_t(7 downto 4)) + x"6");
|
||||
P_Out(Flag_C) <= '1';
|
||||
else
|
||||
P_Out(Flag_C) <= '0';
|
||||
end if;
|
||||
else
|
||||
P_Out(Flag_C) <= Q_t(6);
|
||||
end if;
|
||||
when ALU_OP_BIT=>
|
||||
P_Out(Flag_V) <= BusB(6);
|
||||
when ALU_OP_DEC=>
|
||||
Q_t := std_logic_vector(unsigned(BusA) - 1);
|
||||
when ALU_OP_INC=>
|
||||
Q_t := std_logic_vector(unsigned(BusA) + 1);
|
||||
when others =>
|
||||
null;
|
||||
--EQ1,EQ2,EQ3 passes BusA to Q_t and P_in to P_out
|
||||
end case;
|
||||
|
||||
case Op is
|
||||
when ALU_OP_ADC=>
|
||||
P_Out(Flag_N) <= ADC_N;
|
||||
P_Out(Flag_Z) <= ADC_Z;
|
||||
when ALU_OP_CMP|ALU_OP_SBC|ALU_OP_SAX=>
|
||||
P_Out(Flag_N) <= SBC_N;
|
||||
P_Out(Flag_Z) <= SBC_Z;
|
||||
when ALU_OP_EQ1=>--dont touch P
|
||||
when ALU_OP_BIT=>
|
||||
P_Out(Flag_N) <= BusB(7);
|
||||
if (BusA and BusB) = "00000000" then
|
||||
P_Out(Flag_Z) <= '1';
|
||||
else
|
||||
P_Out(Flag_Z) <= '0';
|
||||
end if;
|
||||
when ALU_OP_ANC=>
|
||||
P_Out(Flag_N) <= Q_t(7);
|
||||
P_Out(Flag_C) <= Q_t(7);
|
||||
if Q_t = "00000000" then
|
||||
P_Out(Flag_Z) <= '1';
|
||||
else
|
||||
P_Out(Flag_Z) <= '0';
|
||||
end if;
|
||||
when others =>
|
||||
P_Out(Flag_N) <= Q_t(7);
|
||||
if Q_t = "00000000" then
|
||||
P_Out(Flag_Z) <= '1';
|
||||
else
|
||||
P_Out(Flag_Z) <= '0';
|
||||
end if;
|
||||
end case;
|
||||
|
||||
if Op=ALU_OP_ARR then
|
||||
-- handled above in ARR code
|
||||
Q <= Q2_t;
|
||||
else
|
||||
Q <= Q_t;
|
||||
end if;
|
||||
end process;
|
||||
|
||||
end;
|
||||
1239
cores/nes/t65/T65_MCode.vhd
Normal file
1239
cores/nes/t65/T65_MCode.vhd
Normal file
File diff suppressed because it is too large
Load Diff
180
cores/nes/t65/T65_Pack.vhd
Normal file
180
cores/nes/t65/T65_Pack.vhd
Normal file
@@ -0,0 +1,180 @@
|
||||
-- ****
|
||||
-- T65(b) core. In an effort to merge and maintain bug fixes ....
|
||||
--
|
||||
-- See list of changes in T65 top file (T65.vhd)...
|
||||
--
|
||||
-- ****
|
||||
-- 65xx compatible microprocessor core
|
||||
--
|
||||
-- FPGAARCADE SVN: $Id: T65_Pack.vhd 1234 2015-02-28 20:14:50Z wolfgang.scherr $
|
||||
--
|
||||
-- Copyright (c) 2002...2015
|
||||
-- Daniel Wallner (jesus <at> opencores <dot> org)
|
||||
-- Mike Johnson (mikej <at> fpgaarcade <dot> com)
|
||||
-- Wolfgang Scherr (WoS <at> pin4 <dot> at>
|
||||
-- Morten Leikvoll ()
|
||||
--
|
||||
-- All rights reserved
|
||||
--
|
||||
-- Redistribution and use in source and synthezised forms, with or without
|
||||
-- modification, are permitted provided that the following conditions are met:
|
||||
--
|
||||
-- Redistributions of source code must retain the above copyright notice,
|
||||
-- this list of conditions and the following disclaimer.
|
||||
--
|
||||
-- Redistributions in synthesized form must reproduce the above copyright
|
||||
-- notice, this list of conditions and the following disclaimer in the
|
||||
-- documentation and/or other materials provided with the distribution.
|
||||
--
|
||||
-- Neither the name of the author nor the names of other contributors may
|
||||
-- be used to endorse or promote products derived from this software without
|
||||
-- specific prior written permission.
|
||||
--
|
||||
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||||
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
|
||||
-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||||
-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
|
||||
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||||
-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
||||
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||||
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
||||
-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||||
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
-- POSSIBILITY OF SUCH DAMAGE.
|
||||
--
|
||||
-- Please report bugs to the author(s), but before you do so, please
|
||||
-- make sure that this is not a derivative work and that
|
||||
-- you have the latest version of this file.
|
||||
--
|
||||
-- Limitations :
|
||||
-- See in T65 top file (T65.vhd)...
|
||||
|
||||
library IEEE;
|
||||
use IEEE.std_logic_1164.all;
|
||||
|
||||
package T65_Pack is
|
||||
|
||||
constant Flag_C : integer := 0;
|
||||
constant Flag_Z : integer := 1;
|
||||
constant Flag_I : integer := 2;
|
||||
constant Flag_D : integer := 3;
|
||||
constant Flag_B : integer := 4;
|
||||
constant Flag_1 : integer := 5;
|
||||
constant Flag_V : integer := 6;
|
||||
constant Flag_N : integer := 7;
|
||||
|
||||
subtype T_Lcycle is std_logic_vector(2 downto 0);
|
||||
constant Cycle_sync :T_Lcycle:="000";
|
||||
constant Cycle_1 :T_Lcycle:="001";
|
||||
constant Cycle_2 :T_Lcycle:="010";
|
||||
constant Cycle_3 :T_Lcycle:="011";
|
||||
constant Cycle_4 :T_Lcycle:="100";
|
||||
constant Cycle_5 :T_Lcycle:="101";
|
||||
constant Cycle_6 :T_Lcycle:="110";
|
||||
constant Cycle_7 :T_Lcycle:="111";
|
||||
|
||||
function CycleNext(c:T_Lcycle) return T_Lcycle;
|
||||
|
||||
type T_Set_BusA_To is
|
||||
(
|
||||
Set_BusA_To_DI,
|
||||
Set_BusA_To_ABC,
|
||||
Set_BusA_To_X,
|
||||
Set_BusA_To_Y,
|
||||
Set_BusA_To_S,
|
||||
Set_BusA_To_P,
|
||||
Set_BusA_To_DA,
|
||||
Set_BusA_To_DAO,
|
||||
Set_BusA_To_DAX,
|
||||
Set_BusA_To_AAX,
|
||||
Set_BusA_To_DONTCARE
|
||||
);
|
||||
|
||||
type T_Set_Addr_To is
|
||||
(
|
||||
Set_Addr_To_SP,
|
||||
Set_Addr_To_ZPG,
|
||||
Set_Addr_To_PBR,
|
||||
Set_Addr_To_BA
|
||||
);
|
||||
|
||||
type T_Write_Data is
|
||||
(
|
||||
Write_Data_DL,
|
||||
Write_Data_ABC,
|
||||
Write_Data_X,
|
||||
Write_Data_Y,
|
||||
Write_Data_S,
|
||||
Write_Data_P,
|
||||
Write_Data_PCL,
|
||||
Write_Data_PCH,
|
||||
Write_Data_AX,
|
||||
Write_Data_AXB,
|
||||
Write_Data_XB,
|
||||
Write_Data_YB,
|
||||
Write_Data_DONTCARE
|
||||
);
|
||||
|
||||
type T_ALU_OP is
|
||||
(
|
||||
ALU_OP_OR, --"0000"
|
||||
ALU_OP_AND, --"0001"
|
||||
ALU_OP_EOR, --"0010"
|
||||
ALU_OP_ADC, --"0011"
|
||||
ALU_OP_EQ1, --"0100" EQ1 does not change N,Z flags, EQ2/3 does.
|
||||
ALU_OP_EQ2, --"0101" Not sure yet whats the difference between EQ2&3. They seem to do the same ALU op
|
||||
ALU_OP_CMP, --"0110"
|
||||
ALU_OP_SBC, --"0111"
|
||||
ALU_OP_ASL, --"1000"
|
||||
ALU_OP_ROL, --"1001"
|
||||
ALU_OP_LSR, --"1010"
|
||||
ALU_OP_ROR, --"1011"
|
||||
ALU_OP_BIT, --"1100"
|
||||
-- ALU_OP_EQ3, --"1101"
|
||||
ALU_OP_DEC, --"1110"
|
||||
ALU_OP_INC, --"1111"
|
||||
ALU_OP_ARR,
|
||||
ALU_OP_ANC,
|
||||
ALU_OP_SAX,
|
||||
ALU_OP_XAA
|
||||
-- ALU_OP_UNDEF--"----"--may be replaced with any?
|
||||
);
|
||||
|
||||
type T_t65_dbg is record
|
||||
I : std_logic_vector(7 downto 0); -- instruction
|
||||
A : std_logic_vector(7 downto 0); -- A reg
|
||||
X : std_logic_vector(7 downto 0); -- X reg
|
||||
Y : std_logic_vector(7 downto 0); -- Y reg
|
||||
S : std_logic_vector(7 downto 0); -- stack pointer
|
||||
P : std_logic_vector(7 downto 0); -- processor flags
|
||||
end record;
|
||||
|
||||
end;
|
||||
|
||||
package body T65_Pack is
|
||||
|
||||
function CycleNext(c:T_Lcycle) return T_Lcycle is
|
||||
begin
|
||||
case(c) is
|
||||
when Cycle_sync=>
|
||||
return Cycle_1;
|
||||
when Cycle_1=>
|
||||
return Cycle_2;
|
||||
when Cycle_2=>
|
||||
return Cycle_3;
|
||||
when Cycle_3=>
|
||||
return Cycle_4;
|
||||
when Cycle_4=>
|
||||
return Cycle_5;
|
||||
when Cycle_5=>
|
||||
return Cycle_6;
|
||||
when Cycle_6=>
|
||||
return Cycle_7;
|
||||
when Cycle_7=>
|
||||
return Cycle_sync;
|
||||
when others=>
|
||||
return Cycle_sync;
|
||||
end case;
|
||||
end CycleNext;
|
||||
|
||||
end T65_Pack;
|
||||
4
cores/nes/t65/t65.qip
Normal file
4
cores/nes/t65/t65.qip
Normal file
@@ -0,0 +1,4 @@
|
||||
set_global_assignment -name VHDL_FILE t65/T65_Pack.vhd
|
||||
set_global_assignment -name VHDL_FILE t65/T65_ALU.vhd
|
||||
set_global_assignment -name VHDL_FILE t65/T65_MCode.vhd
|
||||
set_global_assignment -name VHDL_FILE t65/T65.vhd
|
||||
Reference in New Issue
Block a user