#include "general.h" #include "swdptap.h" static void swdptap_turnaround(uint8_t dir) { static uint8_t olddir = 0; DEBUG("%s", dir ? "\n-> ":"\n<- "); /* Don't turnaround if direction not changing */ if(dir == olddir) return; olddir = dir; if(dir) SWDIO_MODE_FLOAT(); gpio_set(SWCLK_PORT, SWCLK_PIN); gpio_clear(SWCLK_PORT, SWCLK_PIN); if(!dir) SWDIO_MODE_DRIVE(); } static uint8_t swdptap_bit_in(void) { uint16_t ret; ret = gpio_get(SWDIO_PORT, SWDIO_PIN); gpio_set(SWCLK_PORT, SWCLK_PIN); gpio_clear(SWCLK_PORT, SWCLK_PIN); DEBUG("%d", ret?1:0); return ret != 0; } static void swdptap_bit_out(uint8_t val) { DEBUG("%d", val); gpio_set_val(SWDIO_PORT, SWDIO_PIN, val); gpio_set(SWCLK_PORT, SWCLK_PIN); gpio_clear(SWCLK_PORT, SWCLK_PIN); } int swdptap_init(void) { swdptap_reset(); swdptap_seq_out(0xE79E, 16); /* 0b0111100111100111 */ swdptap_reset(); swdptap_seq_out(0, 16); return 0; } void swdptap_reset(void) { swdptap_turnaround(0); /* 50 clocks with TMS high */ for(int i = 0; i < 50; i++) swdptap_bit_out(1); } uint32_t swdptap_seq_in(int ticks) { uint32_t index = 1; uint32_t ret = 0; swdptap_turnaround(1); while(ticks--) { if(swdptap_bit_in()) ret |= index; index <<= 1; } return ret; } uint8_t swdptap_seq_in_parity(uint32_t *ret, int ticks) { uint32_t index = 1; uint8_t parity = 0; *ret = 0; swdptap_turnaround(1); while(ticks--) { if(swdptap_bit_in()) { *ret |= index; parity ^= 1; } index <<= 1; } if(swdptap_bit_in()) parity ^= 1; return parity; } void swdptap_seq_out(uint32_t MS, int ticks) { swdptap_turnaround(0); while(ticks--) { swdptap_bit_out(MS & 1); MS >>= 1; } } void swdptap_seq_out_parity(uint32_t MS, int ticks) { uint8_t parity = 0; swdptap_turnaround(0); while(ticks--) { swdptap_bit_out(MS & 1); parity ^= MS; MS >>= 1; } swdptap_bit_out(parity & 1); }