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mirror of https://github.com/raphnet/dreamcast_usb synced 2024-11-17 22:55:04 -05:00

Add a C implementation to send data from program memory

This commit is contained in:
Raphaël Assénat 2013-11-07 03:38:24 +00:00
parent 3ab2dc3590
commit e71b151d5b
4 changed files with 837 additions and 656 deletions

View File

@ -7,5 +7,5 @@ echo "// Number of samples: $NSAMPLES"
for i in `seq 0 $NSAMPLES`
do
echo "\" in r16, %2\n st z+, r16 \n\" // sample $i "
echo "\" in r16, %1\n st z+, r16 \n\" // sample $i "
done

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@ -18,6 +18,7 @@
* The author may be contacted at raph@raphnet.net
*/
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <util/delay.h>
#include <string.h>
@ -26,7 +27,7 @@
#undef NOLRC
#undef TRACE_RX_START_END
#undef TRACE_DECODED
#undef TRACE_PIN1_BITS
#define TRACE_PIN1_BITS
//
//
@ -41,10 +42,10 @@ void maple_init(void)
}
#define transmitMode() do { PORTC |= 0x03; DDRC |= 0x03; } while(0)
#define inputMode() do { PORTC |= 0x03; DDRC &= ~0x03; } while(0)
#define nop() asm volatile("nop\n");
#define MAPLE_BUF_SIZE 641
static unsigned char maplebuf[MAPLE_BUF_SIZE];
volatile unsigned char maplebuf[MAPLE_BUF_SIZE];
static unsigned char buf_used;
static unsigned char buf_phase;
@ -200,11 +201,10 @@ static int maplebus_decode(unsigned char *data, unsigned int maxlen)
*/
int maple_receiveFrame(unsigned char *data, unsigned int maxlen)
{
unsigned char *tmp = maplebuf;
unsigned char lrc;
unsigned char timeout;
int res, i;
//
// __ _ _ _
// |_____| |_| |_| |_
@ -217,8 +217,10 @@ int maple_receiveFrame(unsigned char *data, unsigned int maxlen)
asm volatile(
" push r30 \n" // 2
" push r31 \n" // 2
" clr %1 \n" // 1 (result=0, no timeout)
" clr %0 \n" // 1 (result=0, no timeout)
" ldi r30, lo8(maplebuf) \n"
" ldi r31, hi8(maplebuf) \n"
// " sbi 0x5, 4 \n" // PB4
// " cbi 0x5, 4 \n"
@ -228,17 +230,17 @@ int maple_receiveFrame(unsigned char *data, unsigned int maxlen)
" dec r19 \n"
" breq timeout \n"
" ldi r18, 255 \n"
" in r17, %2 \n"
" in r17, %1 \n"
"wait_start_inner: \n"
" dec r18 \n"
" breq wait_start_outer \n"
" in r16, %2 \n"
" in r16, %1 \n"
" cp r16, r17 \n"
" breq wait_start_inner \n"
" rjmp start_rx \n"
"timeout:\n"
" inc %1 \n" // 1 for timeout
" inc %0 \n" // 1 for timeout
" sbi 0x5, 4 \n" // PB4
" cbi 0x5, 4 \n"
" jmp done \n"
@ -260,7 +262,7 @@ int maple_receiveFrame(unsigned char *data, unsigned int maxlen)
#endif
" pop r31 \n" // 2
" pop r30 \n" // 2
: "=z"(tmp), "=r"(timeout)
: "=r"(timeout)
: "I" (_SFR_IO_ADDR(PINC))
: "r16","r17","r18","r19") ;
@ -300,6 +302,170 @@ int maple_receiveFrame(unsigned char *data, unsigned int maxlen)
return res-1; // remove lrc
}
static void maple_sendByte(uint8_t data)
{{{
// Phase 1 initial state (pin 1 high, pin 5 low);
PORTC = 0x01;
_delay_us(1);
if (data & 0x80)
PORTC |= 0x02;
nop();
PORTC &= ~0x01;
_delay_us(1);
// Phase 2 initial state (pin 1 low, pin 5 high;
PORTC = 0x02;
_delay_us(1);
if (data & 0x40)
PORTC |= 0x01;
nop();
PORTC &= ~0x02;
_delay_us(1);
// Phase 1 initial state (pin 1 high, pin 5 low);
PORTC = 0x01;
_delay_us(1);
if (data & 0x20)
PORTC |= 0x02;
nop();
PORTC &= ~0x01;
_delay_us(1);
// Phase 2 initial state (pin 1 low, pin 5 high;
PORTC = 0x02;
_delay_us(1);
if (data & 0x10)
PORTC |= 0x01;
nop();
PORTC &= ~0x02;
_delay_us(1);
// Phase 1 initial state (pin 1 high, pin 5 low);
PORTC = 0x01;
_delay_us(1);
if (data & 0x08)
PORTC |= 0x02;
nop();
PORTC &= ~0x01;
_delay_us(1);
// Phase 2 initial state (pin 1 low, pin 5 high;
PORTC = 0x02;
_delay_us(1);
if (data & 0x04)
PORTC |= 0x01;
nop();
PORTC &= ~0x02;
_delay_us(1);
// Phase 1 initial state (pin 1 high, pin 5 low);
PORTC = 0x01;
_delay_us(1);
if (data & 0x02)
PORTC |= 0x02;
nop();
PORTC &= ~0x01;
_delay_us(1);
// Phase 2 initial state (pin 1 low, pin 5 high;
PORTC = 0x02;
_delay_us(1);
if (data & 0x01)
PORTC |= 0x01;
nop();
PORTC &= ~0x02;
_delay_us(1);
}}}
/* Slower C implementation for sending data from program memory. */
void maple_sendRaw_P(unsigned char header_data[4], PGM_P data, unsigned char len)
{
int i;
uint8_t tmp;
uint8_t lrc = 0;
transmitMode();
// Initially both lines are high
PORTC = 0x03;
// Pin 1 falls
PORTC = 0x02;
_delay_us(1);
// Pin 5 falls
PORTC = 0x00;
_delay_us(1);
// 3 pulses on pin 5
PORTC = 0x02;
_delay_us(1);
PORTC = 0x00;
_delay_us(1);
PORTC = 0x02;
_delay_us(1);
PORTC = 0x00;
_delay_us(1);
PORTC = 0x02;
_delay_us(1);
PORTC = 0x00;
_delay_us(1);
PORTC = 0x02;
_delay_us(1);
PORTC = 0x03;
_delay_us(1);
// Phase 1 initial state (pin 1 high, pin 5 low);
PORTC = 0x01;
for (i=0; i<4; i++) {
maple_sendByte(header_data[i]);
lrc ^= header_data[i];
}
for (i=0; i<len; i++) {
// Swap byte order in each word
tmp = pgm_read_byte(data + (i&0xfc) + (3-(i&0x03)));
maple_sendByte(tmp);
lrc ^= tmp;
if (i && (i%8==0)) {
_delay_us(30);
}
}
maple_sendByte(lrc);
// End of frame initial state (Pin 1 high, pin 5 low)
PORTC = 0x01;
_delay_us(1);
// pulse on pin5
PORTC = 0x03;
_delay_us(1);
PORTC = 0x01;
_delay_us(1);
// pin 1 falls
PORTC = 0x00;
_delay_us(1);
// pin 1 pulse
PORTC = 0x01;
_delay_us(1);
PORTC = 0x00;
_delay_us(1);
// pin 1 rise
PORTC = 0x01;
_delay_us(1);
// pin 5 rise
PORTC = 0x03;
inputMode();
}
void maple_sendRaw(unsigned char *data, unsigned char len)
{
int i;
@ -408,15 +574,28 @@ void maple_sendFrame1W(uint8_t cmd, uint8_t dst_addr, uint8_t src_addr, uint32_t
maple_sendFrame(cmd, dst_addr, src_addr, 4, tmp);
}
void maple_sendFrame_P(uint8_t cmd, uint8_t dst_addr, uint8_t src_addr, int data_len, PGM_P data)
{
unsigned char header_data[4];
header_data[0] = data_len >> 2;
header_data[1] = src_addr;
header_data[2] = dst_addr;
header_data[3] = cmd;
// LRC is generated and sent by the function below.
maple_sendRaw_P(header_data, data, data_len);
}
/*
* data is in bus order
*/
void maple_sendFrame(uint8_t cmd, uint8_t dst_addr, uint8_t src_addr, int data_len, uint8_t *data)
{
uint8_t tmp[4 + data_len + 1]; // header, data and LRC
//uint8_t *d;
unsigned char tmp[4 + data_len + 1];
uint8_t lrc=0;
int i;
int len = 4 + data_len + 1;
tmp[0] = data_len >> 2;
tmp[1] = src_addr;
@ -433,6 +612,6 @@ void maple_sendFrame(uint8_t cmd, uint8_t dst_addr, uint8_t src_addr, int data_l
tmp[i] = lrc;
maple_sendRaw(tmp, sizeof(tmp));
maple_sendRaw(tmp, len);
}

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@ -42,4 +42,6 @@ int maple_receiveFrame(uint8_t *data, unsigned int maxlen);
void maple_sendRaw(uint8_t *data, unsigned char len);
void maple_sendFrame_P(uint8_t cmd, uint8_t dst_addr, uint8_t src_addr, int data_len, PGM_P data);
#endif // _maplebus_h__

1282
rxcode.asm

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