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e30c654b | 1 | //----------------------------------------------------------------------------- |
e30c654b | 2 | // Jonathan Westhues, Sept 2005 |
bd20f8f4 | 3 | // |
4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, | |
5 | // at your option, any later version. See the LICENSE.txt file for the text of | |
6 | // the license. | |
7 | //----------------------------------------------------------------------------- | |
8 | // Utility functions used in many places, not specific to any piece of code. | |
e30c654b | 9 | //----------------------------------------------------------------------------- |
bd20f8f4 | 10 | |
f7e3ed82 | 11 | #include "util.h" |
e30c654b | 12 | |
f38a1528 | 13 | void print_result(char *name, uint8_t *buf, size_t len) { |
41863885 | 14 | uint8_t *p = buf; |
f38a1528 | 15 | |
41863885 | 16 | if ( len % 16 == 0 ) { |
17 | for(; p-buf < len; p += 16) | |
18 | Dbprintf("[%s:%d/%d] %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x", | |
f38a1528 | 19 | name, |
20 | p-buf, | |
21 | len, | |
22 | p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15] | |
41863885 | 23 | ); |
24 | } | |
25 | else { | |
26 | for(; p-buf < len; p += 8) | |
27 | Dbprintf("[%s:%d/%d] %02x %02x %02x %02x %02x %02x %02x %02x", | |
28 | name, | |
29 | p-buf, | |
30 | len, | |
31 | p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); | |
32 | } | |
f38a1528 | 33 | } |
34 | ||
195af472 | 35 | size_t nbytes(size_t nbits) { |
665775c8 | 36 | return (nbits >> 3)+((nbits % 8) > 0); |
195af472 | 37 | } |
38 | ||
81cd0474 | 39 | uint32_t SwapBits(uint32_t value, int nrbits) { |
81cd0474 | 40 | uint32_t newvalue = 0; |
5192a0a6 | 41 | for(int i = 0; i < nrbits; i++) { |
81cd0474 | 42 | newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i); |
43 | } | |
44 | return newvalue; | |
45 | } | |
46 | ||
ab3af4fe | 47 | /* |
48 | ref http://www.csm.ornl.gov/~dunigan/crc.html | |
49 | Returns the value v with the bottom b [0,32] bits reflected. | |
50 | Example: reflect(0x3e23L,3) == 0x3e26 | |
51 | */ | |
52 | uint32_t reflect(uint32_t v, int b) { | |
53 | uint32_t t = v; | |
54 | for ( int i = 0; i < b; ++i) { | |
55 | if (t & 1) | |
56 | v |= BITMASK((b-1)-i); | |
57 | else | |
58 | v &= ~BITMASK((b-1)-i); | |
5d15891e | 59 | t >>= 1; |
ab3af4fe | 60 | } |
61 | return v; | |
62 | } | |
63 | ||
41863885 | 64 | void num_to_bytes(uint64_t n, size_t len, uint8_t* dest) { |
e30c654b | 65 | while (len--) { |
f7e3ed82 | 66 | dest[len] = (uint8_t) n; |
e30c654b | 67 | n >>= 8; |
68 | } | |
69 | } | |
70 | ||
41863885 | 71 | uint64_t bytes_to_num(uint8_t* src, size_t len) { |
e30c654b | 72 | uint64_t num = 0; |
2abdfa49 | 73 | while (len--) { |
e30c654b | 74 | num = (num << 8) | (*src); |
75 | src++; | |
76 | } | |
77 | return num; | |
78 | } | |
79 | ||
f38a1528 | 80 | // RotateLeft - Ultralight, Desfire |
41863885 | 81 | void rol(uint8_t *data, const size_t len) { |
f38a1528 | 82 | uint8_t first = data[0]; |
83 | for (size_t i = 0; i < len-1; i++) { | |
84 | data[i] = data[i+1]; | |
85 | } | |
86 | data[len-1] = first; | |
87 | } | |
dd79e03a | 88 | |
f38a1528 | 89 | void lsl (uint8_t *data, size_t len) { |
90 | for (size_t n = 0; n < len - 1; n++) { | |
91 | data[n] = (data[n] << 1) | (data[n+1] >> 7); | |
92 | } | |
93 | data[len - 1] <<= 1; | |
94 | } | |
95 | ||
ab3af4fe | 96 | int32_t le24toh (uint8_t data[3]) { |
f38a1528 | 97 | return (data[2] << 16) | (data[1] << 8) | data[0]; |
98 | } | |
99 | ||
ab3af4fe | 100 | void LEDsoff() { |
e30c654b | 101 | LED_A_OFF(); |
102 | LED_B_OFF(); | |
103 | LED_C_OFF(); | |
104 | LED_D_OFF(); | |
105 | } | |
106 | ||
107 | // LEDs: R(C) O(A) G(B) -- R(D) [1, 2, 4 and 8] | |
ab3af4fe | 108 | void LED(int led, int ms) { |
e30c654b | 109 | if (led & LED_RED) |
110 | LED_C_ON(); | |
111 | if (led & LED_ORANGE) | |
112 | LED_A_ON(); | |
113 | if (led & LED_GREEN) | |
114 | LED_B_ON(); | |
115 | if (led & LED_RED2) | |
116 | LED_D_ON(); | |
117 | ||
118 | if (!ms) | |
119 | return; | |
120 | ||
121 | SpinDelay(ms); | |
122 | ||
123 | if (led & LED_RED) | |
124 | LED_C_OFF(); | |
125 | if (led & LED_ORANGE) | |
126 | LED_A_OFF(); | |
127 | if (led & LED_GREEN) | |
128 | LED_B_OFF(); | |
129 | if (led & LED_RED2) | |
130 | LED_D_OFF(); | |
131 | } | |
132 | ||
e30c654b | 133 | // Determine if a button is double clicked, single clicked, |
134 | // not clicked, or held down (for ms || 1sec) | |
135 | // In general, don't use this function unless you expect a | |
136 | // double click, otherwise it will waste 500ms -- use BUTTON_HELD instead | |
ab3af4fe | 137 | int BUTTON_CLICKED(int ms) { |
e30c654b | 138 | // Up to 500ms in between clicks to mean a double click |
139 | int ticks = (48000 * (ms ? ms : 1000)) >> 10; | |
140 | ||
141 | // If we're not even pressed, forget about it! | |
142 | if (!BUTTON_PRESS()) | |
143 | return BUTTON_NO_CLICK; | |
144 | ||
145 | // Borrow a PWM unit for my real-time clock | |
146 | AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0); | |
147 | // 48 MHz / 1024 gives 46.875 kHz | |
148 | AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10); | |
149 | AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; | |
150 | AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; | |
151 | ||
f7e3ed82 | 152 | uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; |
e30c654b | 153 | |
154 | int letoff = 0; | |
155 | for(;;) | |
156 | { | |
f7e3ed82 | 157 | uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; |
e30c654b | 158 | |
159 | // We haven't let off the button yet | |
160 | if (!letoff) | |
161 | { | |
162 | // We just let it off! | |
163 | if (!BUTTON_PRESS()) | |
164 | { | |
165 | letoff = 1; | |
166 | ||
167 | // reset our timer for 500ms | |
168 | start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
169 | ticks = (48000 * (500)) >> 10; | |
170 | } | |
171 | ||
172 | // Still haven't let it off | |
173 | else | |
174 | // Have we held down a full second? | |
f7e3ed82 | 175 | if (now == (uint16_t)(start + ticks)) |
e30c654b | 176 | return BUTTON_HOLD; |
177 | } | |
178 | ||
179 | // We already let off, did we click again? | |
180 | else | |
181 | // Sweet, double click! | |
182 | if (BUTTON_PRESS()) | |
183 | return BUTTON_DOUBLE_CLICK; | |
184 | ||
185 | // Have we ran out of time to double click? | |
186 | else | |
f7e3ed82 | 187 | if (now == (uint16_t)(start + ticks)) |
e30c654b | 188 | // At least we did a single click |
189 | return BUTTON_SINGLE_CLICK; | |
190 | ||
191 | WDT_HIT(); | |
192 | } | |
193 | ||
194 | // We should never get here | |
195 | return BUTTON_ERROR; | |
196 | } | |
197 | ||
198 | // Determine if a button is held down | |
ab3af4fe | 199 | int BUTTON_HELD(int ms) { |
e30c654b | 200 | // If button is held for one second |
201 | int ticks = (48000 * (ms ? ms : 1000)) >> 10; | |
202 | ||
203 | // If we're not even pressed, forget about it! | |
204 | if (!BUTTON_PRESS()) | |
205 | return BUTTON_NO_CLICK; | |
206 | ||
207 | // Borrow a PWM unit for my real-time clock | |
208 | AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0); | |
209 | // 48 MHz / 1024 gives 46.875 kHz | |
210 | AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10); | |
211 | AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; | |
212 | AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; | |
213 | ||
f7e3ed82 | 214 | uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; |
e30c654b | 215 | |
216 | for(;;) | |
217 | { | |
f7e3ed82 | 218 | uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; |
e30c654b | 219 | |
220 | // As soon as our button let go, we didn't hold long enough | |
221 | if (!BUTTON_PRESS()) | |
222 | return BUTTON_SINGLE_CLICK; | |
223 | ||
224 | // Have we waited the full second? | |
225 | else | |
f7e3ed82 | 226 | if (now == (uint16_t)(start + ticks)) |
e30c654b | 227 | return BUTTON_HOLD; |
228 | ||
229 | WDT_HIT(); | |
230 | } | |
231 | ||
232 | // We should never get here | |
233 | return BUTTON_ERROR; | |
234 | } | |
235 | ||
236 | // attempt at high resolution microsecond timer | |
237 | // beware: timer counts in 21.3uS increments (1024/48Mhz) | |
ab3af4fe | 238 | void SpinDelayUs(int us) { |
b4a6775b | 239 | int ticks = (48 * us) >> 10; |
e30c654b | 240 | |
241 | // Borrow a PWM unit for my real-time clock | |
242 | AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0); | |
b4a6775b | 243 | |
e30c654b | 244 | // 48 MHz / 1024 gives 46.875 kHz |
245 | AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10); | |
246 | AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; | |
247 | AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; | |
248 | ||
f7e3ed82 | 249 | uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; |
e30c654b | 250 | |
251 | for(;;) { | |
f7e3ed82 | 252 | uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; |
253 | if (now == (uint16_t)(start + ticks)) | |
e30c654b | 254 | return; |
255 | ||
256 | WDT_HIT(); | |
257 | } | |
258 | } | |
259 | ||
ab3af4fe | 260 | void SpinDelay(int ms) { |
e30c654b | 261 | // convert to uS and call microsecond delay function |
262 | SpinDelayUs(ms*1000); | |
263 | } | |
264 | ||
265 | /* Similar to FpgaGatherVersion this formats stored version information | |
266 | * into a string representation. It takes a pointer to the struct version_information, | |
267 | * verifies the magic properties, then stores a formatted string, prefixed by | |
268 | * prefix in dst. | |
269 | */ | |
ab3af4fe | 270 | void FormatVersionInformation(char *dst, int len, const char *prefix, void *version_information) { |
e30c654b | 271 | struct version_information *v = (struct version_information*)version_information; |
272 | dst[0] = 0; | |
a61b4976 | 273 | strncat(dst, prefix, len-1); |
e30c654b | 274 | if(v->magic != VERSION_INFORMATION_MAGIC) { |
9783989b | 275 | strncat(dst, "Missing/Invalid version information\n", len - strlen(dst) - 1); |
e30c654b | 276 | return; |
277 | } | |
278 | if(v->versionversion != 1) { | |
9783989b | 279 | strncat(dst, "Version information not understood\n", len - strlen(dst) - 1); |
e30c654b | 280 | return; |
281 | } | |
282 | if(!v->present) { | |
9783989b | 283 | strncat(dst, "Version information not available\n", len - strlen(dst) - 1); |
e30c654b | 284 | return; |
285 | } | |
286 | ||
cba867f2 | 287 | strncat(dst, v->gitversion, len - strlen(dst) - 1); |
e30c654b | 288 | if(v->clean == 0) { |
cba867f2 | 289 | strncat(dst, "-unclean", len - strlen(dst) - 1); |
e30c654b | 290 | } else if(v->clean == 2) { |
cba867f2 | 291 | strncat(dst, "-suspect", len - strlen(dst) - 1); |
e30c654b | 292 | } |
293 | ||
cba867f2 MHS |
294 | strncat(dst, " ", len - strlen(dst) - 1); |
295 | strncat(dst, v->buildtime, len - strlen(dst) - 1); | |
9783989b | 296 | strncat(dst, "\n", len - strlen(dst) - 1); |
e30c654b | 297 | } |
9ca155ba M |
298 | |
299 | // ------------------------------------------------------------------------- | |
300 | // timer lib | |
301 | // ------------------------------------------------------------------------- | |
302 | // test procedure: | |
303 | // | |
304 | // ti = GetTickCount(); | |
305 | // SpinDelay(1000); | |
306 | // ti = GetTickCount() - ti; | |
307 | // Dbprintf("timer(1s): %d t=%d", ti, GetTickCount()); | |
308 | ||
ab3af4fe | 309 | void StartTickCount() { |
f62b5e12 | 310 | // This timer is based on the slow clock. The slow clock frequency is between 22kHz and 40kHz. |
311 | // We can determine the actual slow clock frequency by looking at the Main Clock Frequency Register. | |
312 | uint16_t mainf = AT91C_BASE_PMC->PMC_MCFR & 0xffff; // = 16 * main clock frequency (16MHz) / slow clock frequency | |
313 | // set RealTimeCounter divider to count at 1kHz: | |
314 | AT91C_BASE_RTTC->RTTC_RTMR = AT91C_RTTC_RTTRST | ((256000 + (mainf/2)) / mainf); | |
315 | // note: worst case precision is approx 2.5% | |
9ca155ba M |
316 | } |
317 | ||
318 | /* | |
319 | * Get the current count. | |
320 | */ | |
321 | uint32_t RAMFUNC GetTickCount(){ | |
8f51ddb0 | 322 | return AT91C_BASE_RTTC->RTTC_RTVR;// was * 2; |
9ca155ba M |
323 | } |
324 | ||
8f51ddb0 M |
325 | // ------------------------------------------------------------------------- |
326 | // microseconds timer | |
327 | // ------------------------------------------------------------------------- | |
ab3af4fe | 328 | void StartCountUS() { |
8f51ddb0 M |
329 | AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14); |
330 | // AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC1XC1S_TIOA0; | |
331 | AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE; | |
332 | ||
333 | // fast clock | |
334 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable | |
335 | AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks | |
aaa1a9a2 | 336 | AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR | |
337 | AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET; | |
8f51ddb0 M |
338 | AT91C_BASE_TC0->TC_RA = 1; |
339 | AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000 | |
340 | ||
341 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // timer disable | |
342 | AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from timer 0 | |
1c611bbd | 343 | |
5d15891e | 344 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; |
345 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
8f51ddb0 | 346 | AT91C_BASE_TCB->TCB_BCR = 1; |
5d15891e | 347 | |
348 | while (AT91C_BASE_TC1->TC_CV >= 1); | |
349 | } | |
8f51ddb0 M |
350 | |
351 | uint32_t RAMFUNC GetCountUS(){ | |
0de8e387 | 352 | //return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV / 15) * 10); |
353 | // By suggestion from PwPiwi, http://www.proxmark.org/forum/viewtopic.php?pid=17548#p17548 | |
41863885 | 354 | //return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV * 2) / 3); |
355 | return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV << 1) / 3); | |
5d15891e | 356 | } |
357 | void ResetUSClock(void) { | |
358 | //enable clock of timer and software trigger | |
359 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
360 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
361 | while (AT91C_BASE_TC1->TC_CV >= 1); | |
8f51ddb0 | 362 | } |
b4a6775b | 363 | // attempt at high resolution microsecond timer |
364 | // beware: timer counts in 21.3uS increments (1024/48Mhz) | |
365 | void SpinDelayCountUs(uint32_t us) { | |
8f51ddb0 | 366 | |
b4a6775b | 367 | us += GetCountUS(); |
368 | us -= 6; | |
369 | ||
370 | for(;;) | |
371 | if ( GetCountUS() >= us ) return; | |
372 | } | |
41863885 | 373 | // static uint32_t GlobalUsCounter = 0; |
8f51ddb0 | 374 | |
41863885 | 375 | // uint32_t RAMFUNC GetDeltaCountUS(){ |
376 | // uint32_t g_cnt = GetCountUS(); | |
377 | // uint32_t g_res = g_cnt - GlobalUsCounter; | |
378 | // GlobalUsCounter = g_cnt; | |
379 | // return g_res; | |
380 | // } | |
8f51ddb0 M |
381 | |
382 | ||
1c611bbd | 383 | // ------------------------------------------------------------------------- |
7bc95e2e | 384 | // Timer for iso14443 commands. Uses ssp_clk from FPGA |
1c611bbd | 385 | // ------------------------------------------------------------------------- |
ab3af4fe | 386 | void StartCountSspClk() { |
1c611bbd | 387 | AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1) | (1 << AT91C_ID_TC2); // Enable Clock to all timers |
388 | AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_TIOA1 // XC0 Clock = TIOA1 | |
389 | | AT91C_TCB_TC1XC1S_NONE // XC1 Clock = none | |
390 | | AT91C_TCB_TC2XC2S_TIOA0; // XC2 Clock = TIOA0 | |
391 | ||
392 | // configure TC1 to create a short pulse on TIOA1 when a rising edge on TIOB1 (= ssp_clk from FPGA) occurs: | |
393 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // disable TC1 | |
394 | AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK // TC1 Clock = MCK(48MHz)/2 = 24MHz | |
395 | | AT91C_TC_CPCSTOP // Stop clock on RC compare | |
396 | | AT91C_TC_EEVTEDG_RISING // Trigger on rising edge of Event | |
7bc95e2e | 397 | | AT91C_TC_EEVT_TIOB // Event-Source: TIOB1 (= ssp_clk from FPGA = 13,56MHz/16) |
1c611bbd | 398 | | AT91C_TC_ENETRG // Enable external trigger event |
399 | | AT91C_TC_WAVESEL_UP // Upmode without automatic trigger on RC compare | |
400 | | AT91C_TC_WAVE // Waveform Mode | |
401 | | AT91C_TC_AEEVT_SET // Set TIOA1 on external event | |
402 | | AT91C_TC_ACPC_CLEAR; // Clear TIOA1 on RC Compare | |
403 | AT91C_BASE_TC1->TC_RC = 0x04; // RC Compare value = 0x04 | |
404 | ||
405 | // use TC0 to count TIOA1 pulses | |
7bc95e2e | 406 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // disable TC0 |
1c611bbd | 407 | AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_XC0 // TC0 clock = XC0 clock = TIOA1 |
408 | | AT91C_TC_WAVE // Waveform Mode | |
409 | | AT91C_TC_WAVESEL_UP // just count | |
410 | | AT91C_TC_ACPA_CLEAR // Clear TIOA0 on RA Compare | |
411 | | AT91C_TC_ACPC_SET; // Set TIOA0 on RC Compare | |
412 | AT91C_BASE_TC0->TC_RA = 1; // RA Compare value = 1; pulse width to TC2 | |
413 | AT91C_BASE_TC0->TC_RC = 0; // RC Compare value = 0; increment TC2 on overflow | |
414 | ||
415 | // use TC2 to count TIOA0 pulses (giving us a 32bit counter (TC0/TC2) clocked by ssp_clk) | |
416 | AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKDIS; // disable TC2 | |
417 | AT91C_BASE_TC2->TC_CMR = AT91C_TC_CLKS_XC2 // TC2 clock = XC2 clock = TIOA0 | |
418 | | AT91C_TC_WAVE // Waveform Mode | |
419 | | AT91C_TC_WAVESEL_UP; // just count | |
88e20c9f | 420 | |
63a1d801 | 421 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // enable and reset TC0 |
422 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // enable and reset TC1 | |
423 | AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // enable and reset TC2 | |
9492e0b0 | 424 | |
88e20c9f | 425 | // synchronize the counter with the ssp_frame signal. |
426 | // Note: FPGA must be in any iso14443 mode, otherwise the frame signal would not be present | |
7bc95e2e | 427 | while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME)); // wait for ssp_frame to go high (start of frame) |
9492e0b0 | 428 | while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME); // wait for ssp_frame to be low |
7bc95e2e | 429 | while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)); // wait for ssp_clk to go high |
88e20c9f | 430 | |
7bc95e2e | 431 | // note: up to now two ssp_clk rising edges have passed since the rising edge of ssp_frame |
432 | // it is now safe to assert a sync signal. This sets all timers to 0 on next active clock edge | |
1c611bbd | 433 | AT91C_BASE_TCB->TCB_BCR = 1; // assert Sync (set all timers to 0 on next active clock edge) |
7bc95e2e | 434 | // at the next (3rd) ssp_clk rising edge, TC1 will be reset (and not generate a clock signal to TC0) |
435 | // at the next (4th) ssp_clk rising edge, TC0 (the low word of our counter) will be reset. From now on, | |
436 | // whenever the last three bits of our counter go 0, we can be sure to be in the middle of a frame transfer. | |
437 | // (just started with the transfer of the 4th Bit). | |
88e20c9f | 438 | |
439 | // The high word of the counter (TC2) will not reset until the low word (TC0) overflows. | |
440 | // Therefore need to wait quite some time before we can use the counter. | |
63a1d801 | 441 | while (AT91C_BASE_TC2->TC_CV >= 1); |
442 | } | |
443 | void ResetSspClk(void) { | |
444 | //enable clock of timer and software trigger | |
5d15891e | 445 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; |
446 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
447 | AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
1c611bbd | 448 | } |
449 | ||
7bc95e2e | 450 | uint32_t RAMFUNC GetCountSspClk(){ |
5192a0a6 | 451 | uint32_t tmp_count = (AT91C_BASE_TC2->TC_CV << 16) | AT91C_BASE_TC0->TC_CV; |
452 | if ((tmp_count & 0x0000ffff) == 0) //small chance that we may have missed an increment in TC2 | |
1c611bbd | 453 | return (AT91C_BASE_TC2->TC_CV << 16); |
5192a0a6 | 454 | return tmp_count; |
1c611bbd | 455 | } |
7bc95e2e | 456 |