nuclear@0: #include <stdio.h>
nuclear@1: #include <stdlib.h>
nuclear@0: #include <string.h>
nuclear@0: #include <ctype.h>
nuclear@0: #include <avr/io.h>
nuclear@0: #include <avr/interrupt.h>
nuclear@0: #include "serial.h"
nuclear@0: 
nuclear@1: /* pin assignments:
nuclear@1:  * A[0,7]	data
nuclear@1:  * B[0,7]	A0 - A7
nuclear@1:  * C[0,3]	A8 - A11
nuclear@1:  * D7		CAS3
nuclear@1:  * D6		RAS2
nuclear@1:  * D5		RAS3
nuclear@1:  */
nuclear@1: 
nuclear@1: #define CAS3_BIT	0x80
nuclear@1: #define RAS2_BIT	0x40
nuclear@1: #define RAS3_BIT	0x20
nuclear@1: #define WE_BIT		0x04
nuclear@1: 
nuclear@1: void proc_cmd(char *cmd);
nuclear@1: void cmd_read(char *buf);
nuclear@1: void cmd_write(char *buf);
nuclear@1: void cmd_setcfg(char *buf);
nuclear@1: 
nuclear@1: void dram_init(void);
nuclear@1: void dram_detect(void);
nuclear@1: int memtest(unsigned long addr);
nuclear@1: void dram_refresh(void);
nuclear@1: void dram_write(unsigned long addr, unsigned char val);
nuclear@1: unsigned char dram_read(unsigned long addr);
nuclear@0: 
nuclear@0: #define MAX_INPUT_SIZE	128
nuclear@0: static char input[MAX_INPUT_SIZE];
nuclear@0: static unsigned char inp_cidx;
nuclear@0: 
nuclear@1: /* SIMM access config */
nuclear@1: static int addr_bits;
nuclear@1: static unsigned long addr_mask;
nuclear@1: static int ras_lines = 1;
nuclear@1: static long memsize_kb;	/* derived from the above */
nuclear@1: 
nuclear@1: 
nuclear@0: int main(void)
nuclear@0: {
nuclear@1: 	dram_init();
nuclear@0: 	init_serial(38400);
nuclear@0: 	sei();
nuclear@0: 
nuclear@1: 	printf("Detecting memory ...\n");
nuclear@1: 	dram_detect();
nuclear@1: 
nuclear@1: 	memsize_kb = (1 << (addr_bits * 2)) * 4 * ras_lines;
nuclear@1: 
nuclear@1: 	printf("Address lines: %d\n", addr_bits);
nuclear@1: 	printf("RAS lines: %d\n", ras_lines);
nuclear@1: 	printf("Memory size: %ldmb (%ldkb)\n", memsize_kb >> 10, memsize_kb);
nuclear@1: 	fputs("> ", stdout);
nuclear@0: 
nuclear@0: 	for(;;) {
nuclear@0: 		while(have_input()) {
nuclear@0: 			int c = getchar();
nuclear@0: 			putchar(c);
nuclear@0: 
nuclear@0: 			if(c == '\r' || c == '\n') {
nuclear@0: 				input[inp_cidx] = 0;
nuclear@1: 				proc_cmd(input);
nuclear@0: 				inp_cidx = 0;
nuclear@1: 
nuclear@1: 				fputs("> ", stdout);
nuclear@0: 			} else if(inp_cidx < sizeof input - 1) {
nuclear@0: 				input[inp_cidx++] = c;
nuclear@0: 			}
nuclear@0: 		}
nuclear@1: 
nuclear@1: 		dram_refresh();
nuclear@1: 	}
nuclear@1: 	return 0;
nuclear@1: }
nuclear@1: 
nuclear@1: void proc_cmd(char *cmd)
nuclear@1: {
nuclear@1: 	switch(cmd[0]) {
nuclear@1: 	case 'w':
nuclear@1: 		cmd_write(cmd + 1);
nuclear@1: 		break;
nuclear@1: 
nuclear@1: 	case 'r':
nuclear@1: 		cmd_read(cmd + 1);
nuclear@1: 		break;
nuclear@1: 
nuclear@1: 	case 's':
nuclear@1: 		cmd_setcfg(cmd + 1);
nuclear@1: 		break;
nuclear@1: 
nuclear@1: 	case 'h':
nuclear@1: 		printf("commands:\n");
nuclear@1: 		printf(" w <addr> <value> - write byte to address\n");
nuclear@1: 		printf(" r <addr> - read byte from address\n");
nuclear@1: 		printf(" s <addr_bits|ras_lines> <value>\n");
nuclear@1: 		printf(" h - help\n");
nuclear@1: 		break;
nuclear@1: 	}
nuclear@1: }
nuclear@1: 
nuclear@1: void cmd_read(char *buf)
nuclear@1: {
nuclear@1: 	char *endp;
nuclear@1: 	unsigned long addr;
nuclear@1: 	unsigned char data;
nuclear@1: 
nuclear@1: 	addr = strtol(buf, &endp, 0);
nuclear@1: 	if(endp == buf) {
nuclear@1: 		fprintf(stderr, "invalid argument to write command: %s\n", buf);
nuclear@1: 		return;
nuclear@1: 	}
nuclear@1: 	buf = endp;
nuclear@1: 
nuclear@1: 	data = dram_read(addr);
nuclear@1: 	printf("%04lx: %02x (%u)\n", addr, (unsigned int)data, (unsigned int)data);
nuclear@1: }
nuclear@1: 
nuclear@1: void cmd_write(char *buf)
nuclear@1: {
nuclear@1: 	char *endp;
nuclear@1: 	unsigned long addr;
nuclear@1: 	unsigned char data;
nuclear@1: 
nuclear@1: 	addr = strtol(buf, &endp, 0);
nuclear@1: 	if(endp == buf) {
nuclear@1: 		fprintf(stderr, "invalid address argument to read command: %s\n", buf);
nuclear@1: 		return;
nuclear@1: 	}
nuclear@1: 	buf = endp;
nuclear@1: 
nuclear@1: 	data = strtol(buf, &endp, 0);
nuclear@1: 	if(endp == buf) {
nuclear@1: 		fprintf(stderr, "invalid data argument to read command: %s\n", buf);
nuclear@1: 		return;
nuclear@1: 	}
nuclear@1: 	buf = endp;
nuclear@1: 
nuclear@1: 	dram_write(addr, data);
nuclear@1: 	printf("%04lx: %02x (%u)\n", addr, (unsigned int)data, (unsigned int)data);
nuclear@1: }
nuclear@1: 
nuclear@1: void cmd_setcfg(char *buf)
nuclear@1: {
nuclear@1: 	char *endp;
nuclear@1: 	char *name, *valstr;
nuclear@1: 	long value;
nuclear@1: 
nuclear@1: 	name = buf;
nuclear@1: 	while(*name && isspace(*name)) ++name;
nuclear@1: 	if(!*name) {
nuclear@1: 		fprintf(stderr, "invalid or missing variable name\n");
nuclear@1: 		return;
nuclear@1: 	}
nuclear@1: 	endp = name;
nuclear@1: 	while(*endp && !isspace(*endp)) ++endp;
nuclear@1: 	*endp = 0;
nuclear@1: 
nuclear@1: 	valstr = endp + 1;
nuclear@1: 	value = strtol(valstr, &endp, 0);
nuclear@1: 	if(endp == valstr) {
nuclear@1: 		fprintf(stderr, "invalid or missing variable value: %s\n", valstr);
nuclear@1: 		return;
nuclear@1: 	}
nuclear@1: 
nuclear@1: 	if(strcmp(name, "addr_bits") == 0) {
nuclear@1: 		if(value > 0 && value <= 12) {
nuclear@1: 			addr_bits = value;
nuclear@1: 			printf("Address bits: %ld\n", value);
nuclear@1: 		} else {
nuclear@1: 			fprintf(stderr, "invalid address bits value: %ld\n", value);
nuclear@1: 		}
nuclear@1: 	} else if(strcmp(name, "ras_lines") == 0) {
nuclear@1: 		if(value > 0 && value <= 2) {
nuclear@1: 			ras_lines = value;
nuclear@1: 			printf("RAS lines: %d\n", ras_lines);
nuclear@1: 		} else {
nuclear@1: 			fprintf(stderr, "invalid RAS lines value: %ld\n", value);
nuclear@1: 		}
nuclear@1: 	} else {
nuclear@1: 		fprintf(stderr, "unknown variable: %s\n", name);
nuclear@1: 	}
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_set_data(unsigned char val)
nuclear@1: {
nuclear@1: 	DDRA = 0xff;
nuclear@1: 	PORTA = val;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_release_data(void)
nuclear@1: {
nuclear@1: 	DDRA = 0;
nuclear@1: 	PORTA = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_set_addr(unsigned long addr)
nuclear@1: {
nuclear@1: 	PORTB = addr & 0xff;
nuclear@1: 	PORTC = (addr >> 8) & 3;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_assert_cas(void)
nuclear@1: {
nuclear@1: 	PORTD &= ~CAS3_BIT;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_release_cas(void)
nuclear@1: {
nuclear@1: 	PORTD |= CAS3_BIT;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_assert_ras(unsigned char bits)
nuclear@1: {
nuclear@1: 	PORTD &= ~bits;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_release_ras(unsigned char bits)
nuclear@1: {
nuclear@1: 	PORTD |= bits;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_set_we(void)
nuclear@1: {
nuclear@1: 	PORTD &= ~WE_BIT;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_clear_we(void)
nuclear@1: {
nuclear@1: 	PORTD |= WE_BIT;
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_init(void)
nuclear@1: {
nuclear@1: 	DDRA = 0;	/* port A is the data bus */
nuclear@1: 	PORTA = 0;	/* no pullups when A is input */
nuclear@1: 	DDRB = 0xff;	/* port B is A0-A7 */
nuclear@1: 	DDRC = 0xff;	/* port C (low nibble) is A8-A11 */
nuclear@1: 	DDRD = 0xff;	/* port D are the control lines CAS/RAS/WR */
nuclear@1: 
nuclear@1: 	PORTD = 0xff;	/* deassert all control signals */
nuclear@1: }
nuclear@1: 
nuclear@1: void dram_detect(void)
nuclear@1: {
nuclear@1: 	/* detect how many address bits we've got */
nuclear@1: 	addr_bits = 12;
nuclear@1: 	while(addr_bits > 8) {
nuclear@1: 		printf("addr mask: %lu\n", (unsigned long)((1 << (unsigned long)addr_bits) - 1));
nuclear@1: 		addr_mask = (1 << (unsigned long)addr_bits) - 1;
nuclear@1: 		if(memtest((1 << ((unsigned long)addr_bits * 2)) - 1) == 0) {
nuclear@1: 			break;
nuclear@1: 		}
nuclear@1: 		--addr_bits;
nuclear@1: 	}
nuclear@1: 	if(addr_bits < 1) {
nuclear@1: 		fprintf(stderr, "Failed to detect DRAM configuration (address lines)...\n");
nuclear@1: 		return;
nuclear@1: 	}
nuclear@1: }
nuclear@1: 
nuclear@1: int memtest(unsigned long addr)
nuclear@1: {
nuclear@1: 	int i;
nuclear@1: 	unsigned char pat[] = { 0xf0, 0x0f, 0xaa, 0x55, 0xc0, 0x30, 0x0c, 0x03 };
nuclear@1: 	unsigned char val;
nuclear@1: 
nuclear@1: 	printf("testing address: %lx (a:%d,r:%d)\n", addr, addr_bits, ras_lines);
nuclear@1: 
nuclear@1: 	for(i=0; i<sizeof pat / sizeof *pat; i++) {
nuclear@1: 		dram_write(addr, pat[i]);
nuclear@1: 		if((val = dram_read(addr)) != pat[i]) {
nuclear@1: 			printf("pattern %x failed, got: %x\n", (int)pat[i], val);
nuclear@1: 			return -1;
nuclear@1: 		}
nuclear@0: 	}
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@1: void dram_refresh(void)
nuclear@0: {
nuclear@1: 	dram_assert_cas();
nuclear@1: 	dram_assert_ras(RAS2_BIT | RAS3_BIT);
nuclear@1: 	dram_release_cas();
nuclear@1: 	dram_release_ras(RAS2_BIT | RAS3_BIT);
nuclear@0: }
nuclear@1: 
nuclear@1: void dram_write(unsigned long addr, unsigned char val)
nuclear@1: {
nuclear@1: 	dram_set_data(val);
nuclear@1: 	dram_set_we();
nuclear@1: 	/* set row address */
nuclear@1: 	dram_set_addr((addr >> addr_bits) & addr_mask);
nuclear@1: 	dram_assert_ras(RAS2_BIT);
nuclear@1: 	/* set column address */
nuclear@1: 	dram_set_addr(addr & addr_mask);
nuclear@1: 	dram_assert_cas();
nuclear@1: 	dram_release_ras(RAS2_BIT);
nuclear@1: 	dram_release_cas();
nuclear@1: 	dram_release_data();
nuclear@1: 	dram_clear_we();
nuclear@1: }
nuclear@1: 
nuclear@1: unsigned char dram_read(unsigned long addr)
nuclear@1: {
nuclear@1: 	unsigned char val;
nuclear@1: 
nuclear@1: 	dram_clear_we();
nuclear@1: 	dram_release_data();
nuclear@1: 
nuclear@1: 	/* set row address */
nuclear@1: 	dram_set_addr((addr >> addr_bits) & addr_mask);
nuclear@1: 	dram_assert_ras(RAS2_BIT);
nuclear@1: 	/* set column address */
nuclear@1: 	dram_set_addr(addr & addr_mask);
nuclear@1: 	dram_assert_cas();
nuclear@1: 
nuclear@1: 	val = PINA;
nuclear@1: 
nuclear@1: 	dram_release_ras(RAS2_BIT);
nuclear@1: 	dram_release_cas();
nuclear@1: 
nuclear@1: 	return val;
nuclear@1: }