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mist-devel.mist-board/cores/mist/user_io.v
2018-09-08 21:54:23 +02:00

277 lines
7.0 KiB
Verilog

module user_io(
input SPI_CLK,
input SPI_SS_IO,
output reg SPI_MISO,
input SPI_MOSI,
input [7:0] CORE_TYPE,
// ikbd tdata from io controller to acia
output reg ikbd_strobe_in,
output reg [7:0] ikbd_data_in,
// ikbd data from acia to io controller
output reg ikbd_strobe_out,
input ikbd_data_out_available,
input [7:0] ikbd_data_out,
// four extra joysticks
output reg [5:0] joy0, joy1, joy2, joy3,
// serial data from mfp to io controller
output reg serial_strobe_out,
input serial_data_out_available,
input [7:0] serial_data_out,
// serial status from mfp to io controller
input [63:0] serial_status_out,
// serial data from io controller to mfp
output reg serial_strobe_in,
output reg [7:0] serial_data_in,
// serial status from io controller to mfp
output reg [7:0] serial_status_in,
// parallel data from psg/ym to io controller
output reg parallel_strobe_out,
input parallel_data_out_available,
input [7:0] parallel_data_out,
// midi data from acia to io controller
output reg midi_strobe_out,
input midi_data_out_available,
input [7:0] midi_data_out,
// ethernet interface
input [31:0] eth_status,
// sending mac address from io controller into core
output reg eth_mac_begin,
output reg eth_mac_strobe,
output reg [7:0] eth_mac_byte,
output reg eth_tx_read_begin,
output reg eth_tx_read_strobe,
input [7:0] eth_tx_read_byte,
output reg eth_rx_write_begin,
output reg eth_rx_write_strobe,
output reg [7:0] eth_rx_write_byte,
// on-board buttons and dip switches
output [1:0] BUTTONS,
output [1:0] SWITCHES,
output scandoubler_disable,
output ypbpr
);
// filter spi clock. the 8 bit gate delay is ~2.5ns in total
wire [7:0] spi_sck_D = { spi_sck_D[6:0], SPI_CLK } /* synthesis keep */;
wire spi_sck = (spi_sck && spi_sck_D != 8'h00) || (!spi_sck && spi_sck_D == 8'hff);
reg [3:0] byte_cnt;
reg [6:0] sbuf;
reg [7:0] cmd;
reg [3:0] bit_cnt; // 0..15
reg [5:0] but_sw;
// counter runs 0..7,8..15,8..15,8..15
wire [2:0] tx_bit = ~(bit_cnt[2:0]);
assign BUTTONS = but_sw[1:0];
assign SWITCHES = but_sw[3:2];
assign scandoubler_disable = but_sw[4];
assign ypbpr = but_sw[5];
// prepent "a5" to status to make sure io controller can detect that a core
// doesn't support the command
wire [63+8:0] serial_status_out_x = { 8'ha5, serial_status_out };
always@(negedge spi_sck) begin
if(bit_cnt <= 7)
SPI_MISO <= CORE_TYPE[7-bit_cnt];
else begin
// ikbd acia->io controller
if(cmd == 3) begin
if(!byte_cnt[0])
SPI_MISO <= ikbd_data_out_available;
else
SPI_MISO <= ikbd_data_out[tx_bit];
end
// serial mfp->io controller
if(cmd == 5) begin
if(!byte_cnt[0])
SPI_MISO <= serial_data_out_available;
else
SPI_MISO <= serial_data_out[tx_bit];
end
// parallel psg/ym->io controller
if(cmd == 6) begin
if(!byte_cnt[0])
SPI_MISO <= parallel_data_out_available;
else
SPI_MISO <= parallel_data_out[tx_bit];
end
// midi->io controller
if(cmd == 8) begin
if(!byte_cnt[0])
SPI_MISO <= midi_data_out_available;
else
SPI_MISO <= midi_data_out[tx_bit];
end
// ethernet status
if(cmd == 8'h0a)
SPI_MISO <= eth_status[{~byte_cnt[1:0], tx_bit}];
// read ethernet tx buffer
if(cmd == 8'h0b)
SPI_MISO <= eth_tx_read_byte[tx_bit];
// serial status
if(cmd == 8'h0d)
SPI_MISO <= serial_status_out_x[{4'h8-byte_cnt, tx_bit}];
end
end
always@(posedge spi_sck, posedge SPI_SS_IO) begin
if(SPI_SS_IO == 1) begin
bit_cnt <= 4'd0;
byte_cnt <= 4'd0;
// ikbd (kbd, joysticks, mouse)
ikbd_strobe_in <= 1'b0;
ikbd_strobe_out <= 1'b0;
// USB redirection ports (serial/parallel/midi)
serial_strobe_out <= 1'b0;
parallel_strobe_out <= 1'b0;
midi_strobe_out <= 1'b0;
// ethernet
eth_mac_begin <= 1'b0;
eth_mac_strobe <= 1'b0;
eth_tx_read_begin <= 1'b0;
eth_tx_read_strobe <= 1'b0;
eth_rx_write_begin <= 1'b0;
eth_rx_write_strobe <= 1'b0;
end else begin
sbuf[6:1] <= sbuf[5:0];
sbuf[0] <= SPI_MOSI;
// count 0-7 8-15 8-15 8-15
if(bit_cnt != 4'd15)
bit_cnt <= bit_cnt + 4'd1;
else begin
bit_cnt <= 4'd8;
byte_cnt <= byte_cnt + 4'd1;
end
// command byte finished
if(bit_cnt == 7) begin
cmd[7:1] <= sbuf;
cmd[0] <= SPI_MOSI;
// just finished the mac command byte? -> set begin flag
if( { sbuf, SPI_MOSI} == 8'h09 )
eth_mac_begin <= 1'b1;
if( { sbuf, SPI_MOSI} == 8'h0b ) begin
eth_tx_read_begin <= 1'b1;
eth_tx_read_strobe <= 1'b1;
end
if( { sbuf, SPI_MOSI} == 8'h0c )
eth_rx_write_begin <= 1'b1;
end
if(bit_cnt == 9) begin
ikbd_strobe_in <= 1'b0;
ikbd_strobe_out <= 1'b0;
serial_strobe_in <= 1'b0;
serial_strobe_out <= 1'b0;
parallel_strobe_out <= 1'b0;
midi_strobe_out <= 1'b0;
eth_mac_strobe <= 1'b0;
eth_tx_read_strobe <= 1'b0;
eth_rx_write_strobe <= 1'b0;
end
// payload byte finished
if(bit_cnt == 15) begin
eth_mac_begin <= 1'b0;
if(cmd == 1)
but_sw <= { sbuf[4:0], SPI_MOSI };
// send ikbd byte to acia
if(cmd == 2) begin
ikbd_data_in <= { sbuf, SPI_MOSI };
ikbd_strobe_in <= 1'b1;
end
// give strobe after second ikbd byte (byte_cnt[0] == 1)
if((cmd == 3) && byte_cnt[0])
ikbd_strobe_out <= 1'b1;
// send serial byte to mfp
if(cmd == 4) begin
serial_data_in <= { sbuf, SPI_MOSI };
serial_strobe_in <= 1'b1;
end
// give strobe after second serial byte (byte_cnt[0]==1)
if((cmd == 5) && byte_cnt[0])
serial_strobe_out <= 1'b1;
// give strobe after second parallel byte (byte_cnt[0]==1)
if((cmd == 6) && byte_cnt[0])
parallel_strobe_out <= 1'b1;
// give strobe after second midi byte (byte_cnt[0]==1)
if((cmd == 8) && byte_cnt[0])
midi_strobe_out <= 1'b1;
// send mac address byte to ethernet controller
if(cmd == 9) begin
eth_mac_byte <= { sbuf, SPI_MOSI };
eth_mac_strobe <= 1'b1;
end
// give strobe after each eth byte read
if(cmd == 8'h0b)
eth_tx_read_strobe <= 1'b1;
// give strobe after each eth byte written
if(cmd == 8'h0c) begin
eth_rx_write_byte <= { sbuf, SPI_MOSI };
eth_rx_write_strobe <= 1'b1;
end
// serial_status from io controller
if((cmd == 8'h0d) && (byte_cnt == 1))
serial_status_in <= { sbuf, SPI_MOSI };
// four extra joysticks ...
if(cmd == 8'h10)
joy0 <= { sbuf[4:0], SPI_MOSI };
if(cmd == 8'h11)
joy1 <= { sbuf[4:0], SPI_MOSI };
if(cmd == 8'h12)
joy2 <= { sbuf[4:0], SPI_MOSI };
if(cmd == 8'h13)
joy3 <= { sbuf[4:0], SPI_MOSI };
end
end
end
endmodule