mirror of
https://github.com/V2RetroComputing/analog.git
synced 2024-06-28 15:29:40 +00:00
109 lines
2.9 KiB
C
109 lines
2.9 KiB
C
#include "serial/serialbuffer.h"
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#include "serial/serialrom.h"
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volatile uint8_t *serial_reg = apple_memory + 0xC0A0;
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volatile uint8_t *serial_rx_fifo = private_memory + 0;
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volatile uint8_t serial_rx_wrptr;
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volatile uint8_t serial_rx_rdptr;
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volatile uint8_t *serial_tx_fifo = private_memory + 0x100;
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volatile uint8_t serial_tx_wrptr;
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volatile uint8_t serial_tx_rdptr;
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void serial_rx_advance() {
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if(serial_rx_rdptr != serial_rx_wrptr) {
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serial_rx_rdptr++;
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serial_reg[8] = serial_rx_fifo[serial_rx_rdptr];
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}
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// RXFULL : 6551 has byte(s) ready from RX
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if(serial_rx_wrptr == serial_rx_rdptr) {
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serial_reg[9] &= ~ACIA_STATUS_RXFULL;
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} else {
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serial_reg[9] |= ACIA_STATUS_RXFULL;
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}
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}
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void serial_rx_push(uint8_t value) {
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if((serial_rx_wrptr+1) != serial_rx_rdptr) {
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serial_rx_fifo[serial_rx_wrptr] = value;
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if(serial_rx_wrptr == serial_rx_rdptr) {
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serial_reg[8] = value;
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}
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serial_rx_wrptr++;
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} else {
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serial_reg[9] |= ACIA_STATUS_RXOVER;
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}
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// RXFULL : 6551 has byte(s) ready from RX
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if(serial_rx_wrptr == serial_rx_rdptr) {
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serial_reg[9] &= ~ACIA_STATUS_RXFULL;
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} else {
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serial_reg[9] |= ACIA_STATUS_RXFULL;
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}
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}
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int serial_tx_empty() {
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return serial_rx_rdptr == serial_rx_wrptr;
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}
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uint8_t serial_tx_pop() {
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uint8_t retval;
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if(serial_rx_rdptr != serial_rx_wrptr) {
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retval = serial_rx_fifo[serial_rx_rdptr++];
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}
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// TXEMTY : 6551 able to accept byte(s) for TX
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if((serial_tx_wrptr+1) == serial_tx_rdptr) {
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serial_reg[9] &= ~ACIA_STATUS_TXEMTY;
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} else {
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serial_reg[9] |= ACIA_STATUS_TXEMTY;
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}
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return retval;
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}
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void serial_tx_push(uint8_t value) {
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if((serial_tx_wrptr+1) != serial_tx_rdptr) {
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serial_tx_fifo[serial_tx_wrptr] = value;
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serial_tx_wrptr++;
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}
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// TXEMTY : 6551 able to accept byte(s) for TX
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if((serial_tx_wrptr+1) == serial_tx_rdptr) {
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serial_reg[9] &= ~ACIA_STATUS_TXEMTY;
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} else {
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serial_reg[9] |= ACIA_STATUS_TXEMTY;
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}
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}
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void serial_fifo_init() {
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serial_rx_wrptr = 0;
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serial_rx_rdptr = 0;
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serial_tx_wrptr = 0;
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serial_tx_rdptr = 0;
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serial_reg[0x0] = 0xFF;
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serial_reg[0x1] = 0x02; // Dip Switch 2 : 8N1, No Auto CR after LF,
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serial_reg[0x2] = 0xE0; // Dip Switch 1 : 9600 Baud Communications Mode
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serial_reg[0x3] = 0xFF;
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serial_reg[0x4] = 0xFF;
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serial_reg[0x5] = 0xFF;
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serial_reg[0x6] = 0xFF;
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serial_reg[0x7] = 0xFF;
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serial_reg[0x8] = 0x00; // Read/Write Data Register
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serial_reg[0x9] = 0x10; // Status/Reset Register
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serial_reg[0xA] = 0x0A; // Command Register
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serial_reg[0xB] = 0x1E; // Control Register
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serial_reg[0xC] = 0xFF;
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serial_reg[0xD] = 0xFF;
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serial_reg[0xE] = 0xFF;
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serial_reg[0xF] = 0xFF;
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}
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