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Implement parallel host and peripheral tests

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This commit is contained in:
Jeremy Soller
2020-01-01 19:47:28 -07:00
parent 6c70fa0752
commit e79620989f
2 changed files with 206 additions and 39 deletions
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210
src/board/arduino/mega2560/parallel.c
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@ -41,8 +41,41 @@
/* 1K-Ohm pull-down resistor */ \
PIN(strap_1, 12)
#define DATA_BITS \
DATA_BIT(0) \
DATA_BIT(1) \
DATA_BIT(2) \
DATA_BIT(3) \
DATA_BIT(4) \
DATA_BIT(5) \
DATA_BIT(6) \
DATA_BIT(7)
// Flip odd and even pins
//#define FLIP
#ifdef FLIP
// Mapping of 24-pin ribbon cable to GPIOs (flipped)
static struct Gpio GPIOS[24] = {
GPIO(B, 0), GPIO(B, 1),
GPIO(B, 2), GPIO(B, 3),
GPIO(L, 0), GPIO(L, 1),
GPIO(L, 2), GPIO(L, 3),
GPIO(L, 4), GPIO(L, 5),
GPIO(L, 6), GPIO(L, 7),
GPIO(G, 0), GPIO(G, 1),
GPIO(G, 2), GPIO(D, 7),
GPIO(C, 0), GPIO(C, 1),
GPIO(C, 2), GPIO(C, 3),
GPIO(C, 4), GPIO(C, 5),
GPIO(C, 6), GPIO(C, 7)
};
#else // FLIP
// Mapping of 24-pin ribbon cable to GPIOs
static struct Gpio gpios[24] = {
static struct Gpio GPIOS[24] = {
GPIO(B, 1), GPIO(B, 0),
GPIO(B, 3), GPIO(B, 2),
GPIO(L, 1), GPIO(L, 0),
@ -57,6 +90,9 @@ static struct Gpio gpios[24] = {
GPIO(C, 7), GPIO(C, 6)
};
#endif // FLIP
// Parallel struct definition
// See http://efplus.com/techref/io/parallel/1284/eppmode.htm
struct Parallel {
@ -65,6 +101,13 @@ struct Parallel {
#undef PIN
};
// Parallel struct instance
static struct Parallel PORT = {
#define PIN(N, P) .N = &GPIOS[P - 1],
PINS
#undef PIN
};
// Set port to all high-impedance inputs
void parallel_hiz(struct Parallel * port) {
#define PIN(N, P) \
@ -106,17 +149,7 @@ void parallel_reset(struct Parallel * port) {
gpio_set(port->reset_n, true);
}
#define DATA_BITS \
DATA_BIT(0) \
DATA_BIT(1) \
DATA_BIT(2) \
DATA_BIT(3) \
DATA_BIT(4) \
DATA_BIT(5) \
DATA_BIT(6) \
DATA_BIT(7)
//TODO: address cycle, read cycle, timeout
//TODO: timeout
int parallel_transaction(struct Parallel * port, uint8_t * data, int length, bool read, bool addr) {
int i;
for (i = 0; i < length; i++) {
@ -184,14 +217,153 @@ int parallel_transaction(struct Parallel * port, uint8_t * data, int length, boo
return i;
}
// Parallel struct instance
static struct Parallel PORT = {
#define PIN(N, P) .N = &gpios[P - 1],
PINS
#undef PIN
};
void parallel_host(void) {
printf("Parallel host. Reset to exit\n");
void parallel(void) {
struct Parallel * port = &PORT;
parallel_reset(port);
for (;;) {
int c = getchar();
if (c < 0) break;
putchar(c);
if (c == '\r') {
putchar('\n');
}
uint8_t byte = (uint8_t)c;
parallel_transaction(port, &byte, 1, false, false);
}
parallel_hiz(port);
}
void parallel_peripheral(void) {
printf("Parallel peripheral (WIP, writes only). Reset to exit\n");
struct Parallel * port = &PORT;
parallel_hiz(port);
// Set wait line to low output
gpio_set_dir(port->wait_n, true);
// Strobes are high when inactive
bool last_data_n = true;
bool last_addr_n = true;
for (;;) {
// Read data strobe and edge detect
bool data_n = gpio_get(port->data_n);
bool data_edge = last_data_n && !data_n;
// Read address strobe and edge detect
bool addr_n = gpio_get(port->addr_n);
bool addr_edge = last_addr_n && !addr_n;
// If not in reset
if (gpio_get(port->reset_n)) {
// On the falling edge of either strobe
if (data_edge || addr_edge) {
// Check if read or write cycle
bool read = gpio_get(port->write_n);
// Read data
uint8_t byte = 0;
#define DATA_BIT(B) \
if (gpio_get(port->d ## B)) byte |= (1 << B);
DATA_BITS
#undef DATA_BIT
//TODO: Check if strobe fell while reading
// Set wait line high
gpio_set(port->wait_n, true);
if (data_edge) {
putchar('d');
}
if (addr_edge) {
putchar('a');
}
if (read) {
putchar('<');
} else {
putchar('>');
}
printf("%02X\n", byte);
// Delay 5 usecs
_delay_us(5);
// Set wait line low
gpio_set(port->wait_n, false);
}
}
last_data_n = data_n;
last_addr_n = addr_n;
}
}
void parallel_spy(void) {
printf("Parallel spy. Reset to exit\n");
struct Parallel * port = &PORT;
parallel_hiz(port);
// Strobes are high when inactive
bool last_data_n = true;
bool last_addr_n = true;
for (;;) {
// Read data strobe and edge detect
bool data_n = gpio_get(port->data_n);
bool data_edge = last_data_n && !data_n;
// Read address strobe and edge detect
bool addr_n = gpio_get(port->addr_n);
bool addr_edge = last_addr_n && !addr_n;
// If not in reset
if (gpio_get(port->reset_n)) {
// On the falling edge of either strobe
if (data_edge || addr_edge) {
// Check if read or write cycle
bool read = gpio_get(port->write_n);
// Read data
uint8_t byte = 0;
#define DATA_BIT(B) \
if (gpio_get(port->d ## B)) byte |= (1 << B);
DATA_BITS
#undef DATA_BIT
//TODO: Check if strobe fell while reading
if (data_edge) {
putchar('d');
}
if (addr_edge) {
putchar('a');
}
if (read) {
putchar('<');
} else {
putchar('>');
}
printf("%02X\n", byte);
}
}
last_data_n = data_n;
last_addr_n = addr_n;
}
}