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first checkin for 6502 analysis

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This commit is contained in:
Michael Steil 2010-09-25 21:34:53 +00:00
parent a2f6cca1ba
commit 41c5cb4dcd
1 changed files with 139 additions and 16 deletions
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155
perfect6502.c
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@ -20,7 +20,9 @@
THE SOFTWARE.
*/
int verbose = 0;
int verbose = 1;
#define TEST
/************************************************************
*
@ -521,14 +523,16 @@ recalcNode(nodenum_t node)
* NOTE: "list" as provided by the caller must
* at least be able to hold NODES elements!
*/
//int highest = 0;
void
recalcNodeList(const nodenum_t *source, count_t count)
{
listin_fill(source, count);
for (int j = 0; j < 100; j++) { /* loop limiter */
int j;
for (j = 0; j < 100; j++) { /* loop limiter */
if (!listin_count())
return;
break;
listout_clear();
@ -549,6 +553,10 @@ recalcNodeList(const nodenum_t *source, count_t count)
*/
lists_switch();
}
// if (j > highest) {
// highest = j;
// printf("%d\n", highest);
// }
}
void
@ -586,8 +594,6 @@ writeDataBus(uint8_t d)
uint8_t mRead(uint16_t a)
{
if (verbose)
printf("PEEK($%04X) = $%02X\n", a, memory[a]);
return memory[a];
}
@ -628,8 +634,6 @@ readDataBus()
void
mWrite(uint16_t a, uint8_t d)
{
if (verbose)
printf("POKE $%04X, $%02X\n", a, d);
memory[a] = d;
}
@ -754,7 +758,7 @@ static int cycle;
void
chipStatus()
{
printf("halfcyc:%d phi0:%d AB:%04X D:%02X RnW:%d PC:%04X A:%02X X:%02X Y:%02X SP:%02X P:%02X IR:%02X\n",
printf("halfcyc:%d phi0:%d AB:%04X D:%02X RnW:%d PC:%04X A:%02X X:%02X Y:%02X SP:%02X P:%02X IR:%02X",
cycle,
isNodeHigh(clk0),
readAddressBus(),
@ -767,6 +771,16 @@ chipStatus()
readSP(),
readP(),
readNOTIR() ^ 0xFF);
BOOL clk = isNodeHigh(clk0);
uint16_t a = readAddressBus();
uint8_t d = readDataBus();
if (clk && isNodeHigh(rw))
printf(" R$%04X=$%02X\n", a, memory[a]);
else if (clk && !isNodeHigh(rw))
printf(" W$%04X=$%02X\n", a, d);
else
printf("\n");
}
/************************************************************
@ -884,14 +898,24 @@ halfStep()
}
void
step()
step_quiet()
{
halfStep();
cycle++;
// if (!(cycle % 1000))
// printf("%d\n", cycle);
#ifndef TEST
handle_monitor();
#endif
}
void
step()
{
step_quiet();
if (verbose)
chipStatus();
handle_monitor();
}
/************************************************************
@ -977,10 +1001,17 @@ initChip()
/* hold RESET for 8 cycles */
for (int i = 0; i < 16; i++)
step();
step_quiet();
/* release RESET */
setHigh(res);
#ifdef TEST
for (int i = 0; i < 18 + 2*18; i++)
step_quiet();
cycle = -1;
#endif
}
/************************************************************
@ -989,17 +1020,109 @@ initChip()
*
************************************************************/
#ifndef TEST
int
main()
{
/* set up data structures for efficient emulation */
setupNodesAndTransistors();
/* set initial state of nodes, transistors, inputs; RESET chip */
initChip();
/* set up memory for user program */
init_monitor();
/* set initial state of nodes, transistors, inputs; RESET chip */
initChip();
/* emulate the 6502! */
for (;;)
for (;;) {
step();
if (verbose)
chipStatus();
};
}
#else
#define BRK_LENGTH 2 /* BRK pushes PC + 2 onto the stack */
#define MAX_CYCLES 100
#define SETUP_ADDR 0xF400
#define INSTRUCTION_ADDR 0xF800
#define BRK_VECTOR 0xFC00
struct {
BOOL crash;
int length;
int cycles;
} data[256];
int
main()
{
/* set up data structures for efficient emulation */
setupNodesAndTransistors();
verbose = 0;
for (int opcode = 0x00; opcode <= 0xFF; opcode++) {
printf("testing opcode: $%02X: ", opcode);
memory[0xFFFC] = SETUP_ADDR & 0xFF;
memory[0xFFFD] = SETUP_ADDR >> 8;
uint16_t addr = SETUP_ADDR;
memory[addr++] = 0xA9; /* LDA #P */
memory[addr++] = 0;
memory[addr++] = 0x48; /* PHA */
memory[addr++] = 0xA9; /* LHA #A */
memory[addr++] = 0;
memory[addr++] = 0xA2; /* LDX #X */
memory[addr++] = 0;
memory[addr++] = 0xA0; /* LDY #Y */
memory[addr++] = 0;
memory[addr++] = 0x28; /* PLP */
memory[addr++] = 0x4C; /* JMP */
memory[addr++] = INSTRUCTION_ADDR & 0xFF;
memory[addr++] = INSTRUCTION_ADDR >> 8;
memory[INSTRUCTION_ADDR] = opcode;
memory[0xFFFE] = BRK_VECTOR & 0xFF;
memory[0xFFFF] = BRK_VECTOR >> 8;
memory[BRK_VECTOR] = 0x00; /* loop there */
initChip();
/**************************************************
* find out length of instruction in bytes
**************************************************/
int i;
for (i = 0; i < MAX_CYCLES; i++) {
step();
if (isNodeHigh(clk0) && isNodeHigh(rw) && readAddressBus() == BRK_VECTOR)
break;
};
if (i == MAX_CYCLES) {
data[opcode].crash = YES;
} else {
data[opcode].crash = NO;
uint16_t brk_addr = memory[0x01FC] | memory[0x1FD]<<8;
data[opcode].length = brk_addr - INSTRUCTION_ADDR - BRK_LENGTH;
/**************************************************
* find out length of instruction in cycles
**************************************************/
initChip();
for (i = 0; i < MAX_CYCLES; i++) {
step();
if (isNodeHigh(clk0) && isNodeHigh(rw) && (readNOTIR() ^ 0xFF) == 0x00)
break;
};
data[opcode].cycles = (cycle - 2) / 2;
}
if (data[opcode].crash) {
printf("CRASH\n");
} else {
printf("bytes: %d ", data[opcode].length);
printf("cycles: %d\n", data[opcode].cycles);
}
}
}
#endif