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MicroCoreLabs.Projects/XTMax/Code/XTMax/XTMax.ino
2024-10-11 19:12:58 -07:00

640 lines
22 KiB
C++

//
//
// File Name : XTMax.ino
// Used on :
// Author : Ted Fried, MicroCore Labs
// Creation : 9/7/2024
//
// Description:
// ============
//
// Multi-function 8-bit ISA card using a Teensy 4.1.
//
//------------------------------------------------------------------------
//
// Modification History:
// =====================
//
// Revision 1 9/7/2024
// Initial revision
//
// Revision 2 10/5/2024
// Added support for SD to Parallel interface
//
// Revision 3 10/11/2024
// Added variable wait states for Expanded RAM
// - For 4.77 Mhz, can be changed to zero wait states for Write cycles and two for Read cycles
//
//------------------------------------------------------------------------
//
// Copyright (c) 2024 Ted Fried
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
//------------------------------------------------------------------------
#include <stdint.h>
#include <stdio.h>
// Teensy 4.1 pin assignments
//
#define PIN_BCLK 34
#define PIN_BALE 5
#define PIN_AEN 29
#define PIN_CHRDY_OE_n 28
#define PIN_CHRDY_OUT 6
#define PIN_REFRESH 32
#define PIN_MEMWR_n 33
#define PIN_MEMRD_n 4
#define PIN_IOWR_n 3
#define PIN_IORD_n 2
#define PIN_MUX_DATA_n 31
#define PIN_DATA_OE_n 30
#define PIN_MUX_ADDR_n 9
#define PIN_TRIG_OUT 35
#define PIN_ADDR19 27
#define PIN_ADDR18 26
#define PIN_ADDR17 39
#define PIN_ADDR16 38
#define PIN_ADDR15 21
#define PIN_ADDR14 20
#define PIN_ADDR13 23
#define PIN_ADDR12 22
#define PIN_ADDR11 16
#define PIN_ADDR10 17
#define PIN_ADDR9 41
#define PIN_ADDR8 40
#define PIN_AD7 15
#define PIN_AD6 14
#define PIN_AD5 18
#define PIN_AD4 19
#define PIN_AD3 25
#define PIN_AD2 24
#define PIN_AD1 0
#define PIN_AD0 1
#define PIN_DOUT7 37
#define PIN_DOUT6 36
#define PIN_DOUT5 7
#define PIN_DOUT4 8
#define PIN_DOUT3 13
#define PIN_DOUT2 11
#define PIN_DOUT1 12
#define PIN_DOUT0 10
#define PIN_PSRAM_D3 54 // GPIO9-29
#define PIN_PSRAM_D2 50 // GPIO9-28
#define PIN_PSRAM_D1 49 // GPIO9-27
#define PIN_PSRAM_D0 52 // GPIO9-26
#define PIN_PSRAM_CLK 53 // GPIO9-25
#define PIN_PSRAM_CS_n 48 // GPIO9-24
#define PIN_SD_CS_n 46 // GPIO8-17
#define PIN_SD_MOSI 45 // GPIO8-12
#define PIN_SD_CLK 44 // GPIO8-13
#define PIN_SD_MISO 43 // GPIO8-14
#define ADDRESS_DATA_GPIO6_UNSCRAMBLE ( ((gpio6_int&0xFFFF0000)>>12) | ((gpio6_int&0x3000)>>10) | ((gpio6_int&0xC)>>2) )
#define GPIO7_DATA_OUT_UNSCRAMBLE ( ( (isa_data_out&0xF0)<<12) | (isa_data_out&0x0F) )
#define DATA_OE_n_LOW 0x0
#define DATA_OE_n_HIGH 0x00800000
#define TRIG_OUT_LOW 0x0
#define TRIG_OUT_HIGH 0x10000000
#define MUX_DATA_n_LOW 0x0
#define MUX_DATA_n_HIGH 0x00400000
#define CHRDY_OUT_LOW 0x0
#define CHRDY_OUT_HIGH 0x00000400
#define CHRDY_OE_n_LOW 0x0
#define CHRDY_OE_n_HIGH 0x00040000
#define MUX_ADDR_n_LOW 0x0
#define MUX_ADDR_n_HIGH 0x00000800
#define PSRAM_RESET_VALUE 0x01000000
#define PSRAM_CLK_HIGH 0x02000000
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
uint32_t trigger_out = 0;
uint32_t gpio6_int = 0;
uint32_t gpio9_int = 0;
uint32_t isa_address = 0;
uint32_t page_base_address = 0;
uint32_t psram_address = 0;
uint32_t sd_pin_outputs = 0;
uint8_t data_in = 0;
uint8_t isa_data_out = 0;
uint8_t lpt_data = 0;
uint8_t lpt_status = 0x6F;
uint8_t lpt_control = 0xEC;
uint8_t nibble_in =0;
uint8_t nibble_out =0;
uint8_t read_byte =0;
uint8_t reg_0x260 =0;
uint8_t reg_0x261 =0;
uint8_t reg_0x262 =0;
uint8_t reg_0x263 =0;
uint8_t internal_RAM[0x60000];
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
// Setup Teensy 4.1 IO's
//
void setup() {
pinMode(PIN_BCLK, INPUT);
pinMode(PIN_BALE, INPUT);
pinMode(PIN_AEN, INPUT);
pinMode(PIN_CHRDY_OE_n, OUTPUT);
pinMode(PIN_CHRDY_OUT, OUTPUT);
pinMode(PIN_REFRESH, INPUT);
pinMode(PIN_MEMWR_n, INPUT);
pinMode(PIN_MEMRD_n, INPUT);
pinMode(PIN_IOWR_n, INPUT);
pinMode(PIN_IORD_n, INPUT);
pinMode(PIN_MUX_DATA_n, OUTPUT);
pinMode(PIN_DATA_OE_n, OUTPUT);
pinMode(PIN_MUX_ADDR_n, OUTPUT);
pinMode(PIN_TRIG_OUT, OUTPUT);
pinMode(PIN_ADDR19, INPUT);
pinMode(PIN_ADDR18, INPUT);
pinMode(PIN_ADDR17, INPUT);
pinMode(PIN_ADDR16, INPUT);
pinMode(PIN_ADDR15, INPUT);
pinMode(PIN_ADDR14, INPUT);
pinMode(PIN_ADDR13, INPUT);
pinMode(PIN_ADDR12, INPUT);
pinMode(PIN_ADDR11, INPUT);
pinMode(PIN_ADDR10, INPUT);
pinMode(PIN_ADDR9, INPUT);
pinMode(PIN_ADDR8, INPUT);
pinMode(PIN_AD7, INPUT);
pinMode(PIN_AD6, INPUT);
pinMode(PIN_AD5, INPUT);
pinMode(PIN_AD4, INPUT);
pinMode(PIN_AD3, INPUT);
pinMode(PIN_AD2, INPUT);
pinMode(PIN_AD1, INPUT);
pinMode(PIN_AD0, INPUT);
pinMode(PIN_DOUT7, OUTPUT);
pinMode(PIN_DOUT6, OUTPUT);
pinMode(PIN_DOUT5, OUTPUT);
pinMode(PIN_DOUT4, OUTPUT);
pinMode(PIN_DOUT3, OUTPUT);
pinMode(PIN_DOUT2, OUTPUT);
pinMode(PIN_DOUT1, OUTPUT);
pinMode(PIN_DOUT0, OUTPUT);
pinMode(PIN_PSRAM_CLK, OUTPUT);
pinMode(PIN_PSRAM_CS_n, OUTPUT);
pinMode(PIN_PSRAM_D3, INPUT);
pinMode(PIN_PSRAM_D2, INPUT);
pinMode(PIN_PSRAM_D1, INPUT);
pinMode(PIN_PSRAM_D0, OUTPUT);
pinMode(PIN_SD_CLK, OUTPUT);
pinMode(PIN_SD_CS_n, OUTPUT);
pinMode(PIN_SD_MOSI, OUTPUT);
pinMode(PIN_SD_MISO, INPUT_PULLUP);
GPIO9_DR = PSRAM_RESET_VALUE; // Set CLK=0, CS_n=1, DATA=0
digitalWriteFast(PIN_CHRDY_OE_n, 0x1);
digitalWriteFast(PIN_CHRDY_OUT, 0x0);
digitalWriteFast(PIN_DATA_OE_n, 0x1);
digitalWriteFast(PIN_MUX_ADDR_n, 0x0);
digitalWriteFast(PIN_MUX_DATA_n, 0x1);
digitalWriteFast(PIN_TRIG_OUT, 0x1);
//noInterrupts(); // Disable Teensy interupts
//Serial.begin(9600);
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void PSRAM_Write_Clk_Cycle() {
GPIO9_DR = (nibble_out&0xF) << 26; // Drive nibble data , CLK=0 , CS_n=0
delayNanoseconds(1);
GPIO9_DR = (nibble_out<<26) | PSRAM_CLK_HIGH; // Drive nibble data and CLK=1
delayNanoseconds(1);
return;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void PSRAM_Read_Clk_Cycle() {
GPIO9_DR = 0x0; // Drive CLK=0 , CS_n=0
delayNanoseconds(1);
GPIO9_DR = PSRAM_CLK_HIGH; // Drive CLK=1
delayNanoseconds(1);
nibble_in = (GPIO9_DR>>26) & 0xF; // Sample nibble data
return;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void PSRAM_Configure() {
delayMicroseconds(200);
nibble_out = 0x0; PSRAM_Write_Clk_Cycle(); // Set PSRAM to Quad Mode 0x35
nibble_out = 0x0; PSRAM_Write_Clk_Cycle();
nibble_out = 0x1; PSRAM_Write_Clk_Cycle();
nibble_out = 0x1; PSRAM_Write_Clk_Cycle();
nibble_out = 0x0; PSRAM_Write_Clk_Cycle();
nibble_out = 0x1; PSRAM_Write_Clk_Cycle();
nibble_out = 0x0; PSRAM_Write_Clk_Cycle();
nibble_out = 0x1; PSRAM_Write_Clk_Cycle();
GPIO9_DR = PSRAM_RESET_VALUE; // Drive CLK=0 , CS_n=1
GPIO9_GDIR = 0x3F000000; // Change Data[3:0] to outputs quickly
return;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline uint8_t PSRAM_Read(uint32_t address_in) {
// Send Command = Quad Read = 0x0B
//
nibble_out = 0x0; PSRAM_Write_Clk_Cycle();
nibble_out = 0xB; PSRAM_Write_Clk_Cycle();
// Send 24-bit address in four clock cycles
//
nibble_out = address_in >> 20; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 16; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 12; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 8; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 4; PSRAM_Write_Clk_Cycle();
nibble_out = address_in; PSRAM_Write_Clk_Cycle();
//GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_LOW; // De-assert CHRDY early for 4.77 Mhz
// Four clocks of hi-Z - Make PSRAM Data signals hi-Z during this time
//
GPIO9_GDIR = 0x03000000; // Change Data[3:0] to inputs quickly
PSRAM_Write_Clk_Cycle();
PSRAM_Write_Clk_Cycle();
PSRAM_Write_Clk_Cycle();
PSRAM_Write_Clk_Cycle();
// Clock in the data
//
PSRAM_Read_Clk_Cycle(); read_byte = nibble_in;
PSRAM_Read_Clk_Cycle(); read_byte = (read_byte<<4) | nibble_in;
GPIO9_DR = PSRAM_RESET_VALUE; // Drive CLK=0 , CS_n=1
GPIO9_GDIR = 0x3F000000; // Change Data[3:0] to outputs quickly
return read_byte;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline uint8_t PSRAM_Write(uint32_t address_in , int8_t local_data) {
// Send Command = Quad Write = 0x02
//
nibble_out = 0x0; PSRAM_Write_Clk_Cycle();
nibble_out = 0x2; PSRAM_Write_Clk_Cycle();
// Send 24-bit address in four clock cycles
//
nibble_out = address_in >> 20; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 16; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 12; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 8; PSRAM_Write_Clk_Cycle();
nibble_out = address_in >> 4; PSRAM_Write_Clk_Cycle();
nibble_out = address_in; PSRAM_Write_Clk_Cycle();
//GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_LOW; // De-assert CHRDY early for 4.77 Mhz
// Send byte data in twp clock cycles
//
nibble_out = local_data >> 4; PSRAM_Write_Clk_Cycle();
nibble_out = local_data; PSRAM_Write_Clk_Cycle();
GPIO9_DR = PSRAM_RESET_VALUE; // Drive CLK=0 , CS_n=1
return read_byte;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void Mem_Read_Cycle() {
isa_address = ADDRESS_DATA_GPIO6_UNSCRAMBLE;
if ( (isa_address>=0xE0000) && (isa_address<0xF0000) ) { // Expanded RAM page frame
page_base_address = (isa_address & 0xFC000);
if (page_base_address == 0xEC000) { psram_address = (reg_0x263<<14) | (isa_address & 0x03FFF); }
else if (page_base_address == 0xE8000) { psram_address = (reg_0x262<<14) | (isa_address & 0x03FFF); }
else if (page_base_address == 0xE4000) { psram_address = (reg_0x261<<14) | (isa_address & 0x03FFF); }
else if (page_base_address == 0xE0000) { psram_address = (reg_0x260<<14) | (isa_address & 0x03FFF); }
GPIO7_DR = MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_LOW + DATA_OE_n_LOW ; // Assert CHRDY_n=0 to begin wait states
isa_data_out = PSRAM_Read(psram_address);
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out; // Output data
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_LOW; // De-assert CHRDY
while ( (gpio9_int&0xF0) != 0xF0 ) { gpio9_int = GPIO9_DR; } // Wait here until cycle is complete
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
else if ( (isa_address>=0x40000) && (isa_address<0xA0000) ) { // 384 KB
isa_data_out = internal_RAM[isa_address-0x40000];
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_LOW;
while ( (gpio9_int&0xF0) != 0xF0 ) { gpio9_int = GPIO9_DR; } // Wait here until cycle is complete
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
return;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void Mem_Write_Cycle() {
isa_address = ADDRESS_DATA_GPIO6_UNSCRAMBLE;
if ( (isa_address>=0xE0000) && (isa_address<0xF0000) ) { // Expanded RAM page frame
page_base_address = (isa_address & 0xFC000);
if (page_base_address == 0xEC000) { psram_address = (reg_0x263<<14) | (isa_address & 0x03FFF); }
else if (page_base_address == 0xE8000) { psram_address = (reg_0x262<<14) | (isa_address & 0x03FFF); }
else if (page_base_address == 0xE4000) { psram_address = (reg_0x261<<14) | (isa_address & 0x03FFF); }
else if (page_base_address == 0xE0000) { psram_address = (reg_0x260<<14) | (isa_address & 0x03FFF); }
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_HIGH + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_LOW + CHRDY_OE_n_LOW + DATA_OE_n_HIGH; // Steer data mux to Data[7:0] and Assert CHRDY_n=0 to begin wait states
delayNanoseconds(10); // Wait some time for buffers to switch from address to data
gpio6_int = GPIO6_DR;
data_in = 0xFF & ADDRESS_DATA_GPIO6_UNSCRAMBLE;
PSRAM_Write(psram_address , data_in);
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_LOW + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH; // De-assert CHRDY
while ( (gpio9_int&0xF0) != 0xF0 ) { // Wait here until cycle is complete
gpio6_int = GPIO6_DR; // Needed?
gpio9_int = GPIO9_DR;
}
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
else if ( (isa_address>=0x40000) && (isa_address<0xA0000) ) { // 384 KB
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_HIGH + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_LOW + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
while ( (gpio9_int&0xF0) != 0xF0 ) { // Wait here until cycle is complete
gpio6_int = GPIO6_DR; // Needed?
gpio9_int = GPIO9_DR;
}
internal_RAM[isa_address-0x40000] = 0xFF & ADDRESS_DATA_GPIO6_UNSCRAMBLE;
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
return;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void IO_Read_Cycle() {
isa_address = 0xFFFF & ADDRESS_DATA_GPIO6_UNSCRAMBLE;
if ((isa_address&0x0FFC)==0x260 ) { // Location of 16 KB Expanded Memory page frame pointers
switch (isa_address) {
case 0x260: isa_data_out = reg_0x260; break;
case 0x261: isa_data_out = reg_0x261; break;
case 0x262: isa_data_out = reg_0x262; break;
case 0x263: isa_data_out = reg_0x263; break;
}
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_LOW;
while ( (gpio9_int&0xF0) != 0xF0 ) { gpio9_int = GPIO9_DR; } // Wait here until cycle is complete
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
else if ((isa_address&0x0FF8)==0x378 ) { // Location of Parallel Port
if ((GPIO8_DR&0x00004000)!=0) { lpt_status = lpt_status | 0xFF; }
else { lpt_status = lpt_status & 0x00; } // PIN_SD_MISO 43 GPIO8-14
switch (isa_address) {
case 0x378: isa_data_out = lpt_data; break;
case 0x379: isa_data_out = lpt_status; break;
case 0x37A: isa_data_out = lpt_control; break;
}
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_LOW;
while ( (gpio9_int&0xF0) != 0xF0 ) { gpio9_int = GPIO9_DR; } // Wait here until cycle is complete
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
return;
}
// --------------------------------------------------------------------------------------------------
// --------------------------------------------------------------------------------------------------
inline void IO_Write_Cycle() {
isa_address = 0xFFFF & ADDRESS_DATA_GPIO6_UNSCRAMBLE;
if ((isa_address&0x0FFC)==0x260 ) { // Location of 16 KB Expanded Memory page frame pointers
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_HIGH + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_LOW + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
while ( (gpio9_int&0xF0) != 0xF0 ) { // Wait here until cycle is complete
gpio6_int = GPIO6_DR; // Needed?
gpio9_int = GPIO9_DR;
}
data_in = 0xFF & ADDRESS_DATA_GPIO6_UNSCRAMBLE;
switch (isa_address) {
case 0x260: reg_0x260 = data_in; break;
case 0x261: reg_0x261 = data_in; break;
case 0x262: reg_0x262 = data_in; break;
case 0x263: reg_0x263 = data_in; break;
}
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
else if ((isa_address&0x0FF8)==0x378 ) { // Location of Parallel Port
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_HIGH + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_LOW + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
while ( (gpio9_int&0xF0) != 0xF0 ) { // Wait here until cycle is complete
gpio6_int = GPIO6_DR; // Needed?
gpio9_int = GPIO9_DR;
}
data_in = 0xFF & ADDRESS_DATA_GPIO6_UNSCRAMBLE;
switch (isa_address) {
case 0x378: lpt_data = data_in; break;
case 0x37A: lpt_control = data_in; break;
}
sd_pin_outputs = ((lpt_data&0x4)<<15) | ((lpt_data&0x2)<<12) | ((lpt_data&0x1)<<12); // lpt_data[2]=SD_CS_n - lpt_data[1]=SD_CLK - lpt_data[0]=SD_MOSI
//trigger_out = ((lpt_data&0x1)<<28); // SD_MOSI
//trigger_out = ((lpt_data&0x2)<<27); // SD_CLK
//trigger_out = ((lpt_data&0x4)<<26); // SD_CS_n
GPIO7_DR = GPIO7_DATA_OUT_UNSCRAMBLE + MUX_ADDR_n_LOW + CHRDY_OUT_LOW + trigger_out;
GPIO8_DR = sd_pin_outputs + MUX_DATA_n_HIGH + CHRDY_OE_n_HIGH + DATA_OE_n_HIGH;
}
return;
}
// -------------------------------------------------
//
// Main loop
//
// -------------------------------------------------
void loop() {
// Give Teensy 4.1 a moment
//
//delay (1000);
PSRAM_Configure();
while (1) {
gpio6_int = GPIO6_DR;
gpio9_int = GPIO9_DR;
if ((gpio9_int&0x80000010)==0) IO_Read_Cycle(); // Isolate and check AEN and IO Rd/Wr
else if ((gpio9_int&0x80000020)==0) IO_Write_Cycle();
else if ((gpio9_int&0x00000040)==0) Mem_Read_Cycle();
else if ((gpio9_int&0x00000080)==0) Mem_Write_Cycle();
}
}