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/*
* SIO communication library for PSXSDK.
* Originally written by Shendo.
* Thanks to Martin Korth of the NO$PSX for documentation.
*
* This library is accessing SIO registers directly, no BIOS routines are used.
*/
#include <psx.h>
#include <psxsio.h>
#include <stdio.h>
void SIOStart(int bitrate)
{
/*Set to 8N1 mode with desired bitrate*/
SIOStartEx(bitrate, SIO_DATA_LEN_8, SIO_PARITY_NONE, SIO_STOP_BIT_1);
}
void SIOStartEx(int bitrate, int datalength, int parity, int stopbit)
{
/*Set SIO_MODE register, bitrate reload factor set to MUL16 by default*/
SIO_MODE = SIO_REL_MUL16 | (datalength << 2) | (parity << 4) | (stopbit << 6);
/*Reset SIO_CTRL register.*/
SIO_CTRL = 0;
/*Set TX and RT to enabled, no handshaking signals.*/
SIO_CTRL = 1 | (1 << 2);
/*Calculate bitrate reload value based on the given bitrate
* Reload = SystemClock (33 Mhz) / (Factor (MULI16) * bitrate)*/
SIO_BPSV = 0x204CC00 / (16 * bitrate);
}
void SIOStop()
{
/*Set all SIO related registers to zero*/
SIO_MODE = 0;
SIO_CTRL = 0;
SIO_BPSV = 0;
}
unsigned char SIOReadByte()
{
return (unsigned char)SIO_TX_RX;
}
void SIOSendByte(unsigned char data)
{
SIO_TX_RX = data;
}
int SIOCheckInBuffer()
{
/*Return status of RX FIFO*/
return (SIO_STAT & 0x2)>0;
}
int SIOCheckOutBuffer()
{
/*Return status of TX Ready flag*/
return (SIO_STAT & 0x4)>0;
}
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