]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * (C) Copyright 2018 Leo C. <erbl259-lmu@yahoo.de> | |
3 | * | |
4 | * SPDX-License-Identifier: GPL-2.0 | |
5 | */ | |
6 | ||
7 | #include "cmd_cpu.h" | |
8 | //#include <ctype.h> | |
9 | #include <util/atomic.h> | |
10 | ||
11 | #include "z80-if.h" | |
12 | #include "con-utils.h" | |
13 | #include "env.h" | |
14 | #include "eval_arg.h" | |
15 | #include "timer.h" | |
16 | #include "getopt-min.h" | |
17 | #include "debug.h" | |
18 | ||
19 | /* hack to get Z180 loadfile into flash memory */ | |
20 | #define const const FLASH | |
21 | #include "../z180/cpuinfo.h" | |
22 | #undef const | |
23 | ||
24 | ||
25 | /* | |
26 | * delay for <count> ms... | |
27 | */ | |
28 | static void test_delay(uint32_t count) | |
29 | { | |
30 | uint32_t ts = get_timer(0); | |
31 | ||
32 | while (get_timer(ts) <= count); | |
33 | } | |
34 | ||
35 | static int32_t z80_measure_phi(uint8_t cycles, uint16_t wait_ms) | |
36 | { | |
37 | uint16_t ref_stop; | |
38 | uint16_t ref_ovfl; | |
39 | uint32_t x_freq; | |
40 | uint8_t eimsk_save,eicrb_save; | |
41 | ||
42 | ||
43 | ATOMIC_BLOCK(ATOMIC_FORCEON) { | |
44 | /* Save state and disable INT6 */ | |
45 | eimsk_save = EIMSK; | |
46 | EIMSK &= ~_BV(INT6); | |
47 | /* Save state and set INT6 for falling edge */ | |
48 | eicrb_save = EICRB; | |
49 | EICRB = (eicrb_save & ~(0b11 << ISC60)) | (0b10 << ISC60); | |
50 | } | |
51 | ||
52 | PRR1 &= ~_BV(PRTIM3); | |
53 | TCCR3A = 0; | |
54 | TCCR3B = 0b000<<CS30; /* stop counter */ | |
55 | TCNT3 = 0; | |
56 | TIFR3 = _BV(TOV3); | |
57 | ref_ovfl = 0; | |
58 | ||
59 | ATOMIC_BLOCK(ATOMIC_FORCEON) { | |
60 | /* Reset pending int */ | |
61 | EIFR = _BV(INTF6); | |
62 | /* Wait for falling edge */ | |
63 | while ((EIFR & _BV(INTF6)) == 0) | |
64 | ; | |
65 | OCR4B = TCNT4; | |
66 | TCCR3B = 0b110<<CS30; /* Count falling edges on T3 (==INT6) */ | |
67 | TIFR4 = _BV(OCF4B); /* clear compare match flag */ | |
68 | } | |
69 | while (ref_ovfl < 60) { | |
70 | ATOMIC_BLOCK(ATOMIC_FORCEON) { | |
71 | if ((TIFR4 & _BV(OCF4B)) != 0) { | |
72 | TIFR4 = _BV(OCF4B); | |
73 | ref_ovfl++; | |
74 | } | |
75 | } | |
76 | } | |
77 | ||
78 | ATOMIC_BLOCK(ATOMIC_FORCEON) { | |
79 | EIFR = _BV(INTF6); | |
80 | for (;;) { | |
81 | if (EIFR & _BV(INTF6)) | |
82 | break; | |
83 | if (TIFR4 & _BV(OCF4B)) { | |
84 | if (EIFR & _BV(INTF6)) | |
85 | break; | |
86 | TIFR4 = _BV(OCF4B); | |
87 | if (EIFR & _BV(INTF6)) | |
88 | break; | |
89 | ref_ovfl++; | |
90 | if (EIFR & _BV(INTF6)) | |
91 | break; | |
92 | if (ref_ovfl == 0) | |
93 | break; | |
94 | } | |
95 | } | |
96 | ref_stop = TCNT4; | |
97 | TCCR3B = 0b000<<CS30; /* stop counter */ | |
98 | if ((TIFR4 & _BV(OCF4B)) != 0) { | |
99 | TIFR4 = _BV(OCF4B); | |
100 | if (ref_ovfl) | |
101 | ref_ovfl++; | |
102 | } | |
103 | } | |
104 | ||
105 | if (ref_ovfl == 0) | |
106 | x_freq = 0xFFFFFFFE; | |
107 | else | |
108 | { | |
109 | uint32_t ref_cnt = (ref_stop - OCR4B) + ((uint32_t)ref_ovfl << 16); | |
110 | ||
111 | x_freq = TCNT3; /* x_cnt (17 bit) */ | |
112 | if ((TIFR3 & _BV(TOV3)) != 0) | |
113 | x_freq += 1UL << 16; | |
114 | uint32_t x_cnt = x_freq; | |
115 | x_freq *= cycles; | |
116 | ||
117 | x_freq = ((uint64_t) x_freq * getenv_ulong(PSTR(ENV_FMON), 10, F_CPU) + (ref_cnt / 2))/ ref_cnt; | |
118 | ||
119 | debug("ref_start: %6u, ref_stop: %6u, ref_ovfl: %4u, ref_cnt: %9lu\n" | |
120 | " TCNT3: %6u, x_cnt: %6lu, cycles: %3u, xfreq: %9lu\n", | |
121 | OCR4B, ref_stop, ref_ovfl, ref_cnt, | |
122 | TCNT3, x_cnt, cycles, x_freq); | |
123 | ||
124 | /* round to 5 decimal digits */ | |
125 | uint8_t sc = 0; | |
126 | while (x_freq >= 100000UL) { | |
127 | x_freq = (x_freq + 5)/10; | |
128 | ++sc; | |
129 | } | |
130 | while (sc--) | |
131 | x_freq *= 10; | |
132 | } | |
133 | ||
134 | /* Stop Timer */ | |
135 | TCCR3B = 0; | |
136 | PRR1 |= _BV(PRTIM3); | |
137 | ||
138 | ATOMIC_BLOCK(ATOMIC_FORCEON) { | |
139 | /* Restore INT6 */ | |
140 | #if 0 /* wtf? */ | |
141 | eicrb_save = EICRB; | |
142 | EICRB = (EICRB & ~(0b11 << ISC60)) | (eicrb_save & (0b11 << ISC60)); | |
143 | #endif | |
144 | EICRB = eicrb_save; | |
145 | if ((eimsk_save & _BV(INT6)) != 0) | |
146 | EIMSK |= _BV(INT6); | |
147 | /* Reset pending int */ | |
148 | EIFR = _BV(INTF6); | |
149 | } | |
150 | ||
151 | return (int32_t) x_freq; | |
152 | } | |
153 | ||
154 | ||
155 | static const FLASH char * const FLASH cpu_strings[] = { | |
156 | FSTR("Unknown CPU"), | |
157 | FSTR("8080"), | |
158 | FSTR("8085"), | |
159 | FSTR("Z80"), | |
160 | FSTR("x180"), | |
161 | FSTR("HD64180"), | |
162 | FSTR("Z80180"), | |
163 | FSTR("Z80S180"), | |
164 | }; | |
165 | ||
166 | command_ret_t do_cpuchk(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc UNUSED, char * const argv[] UNUSED) | |
167 | { | |
168 | uint8_t done = 0; | |
169 | uint8_t cputype; | |
170 | ERRNUM err = ESUCCESS; | |
171 | uint8_t ram_save[cpuinfo_length]; | |
172 | ||
173 | if (z80_bus_state() & ZST_RUNNING) { | |
174 | err = ERUNNING; | |
175 | } else { | |
176 | z80_bus_request_or_exit(); | |
177 | z80_read_block(ram_save, 0, cpuinfo_length); | |
178 | z80_load_mem(0, cpuinfo, | |
179 | &cpuinfo_sections, | |
180 | cpuinfo_address, | |
181 | cpuinfo_length_of_sections); | |
182 | z80_bus_cmd(Release); | |
183 | ||
184 | if (argv[1] && (argv[1][0] == 'n')) | |
185 | goto donot; | |
186 | ||
187 | z80_bus_cmd(Run); | |
188 | ||
189 | clear_ctrlc(); /* forget any previous Control C */ | |
190 | while (done != 0xFF) { | |
191 | _delay_ms(8); | |
192 | /* check for ctrl-c to abort... */ | |
193 | if (had_ctrlc() || ctrlc()) { | |
194 | err = EINTR; | |
195 | break; | |
196 | } | |
197 | z80_bus_cmd(Request); | |
198 | done = z80_read(3); | |
199 | if (done == 0xFF) | |
200 | cputype = z80_read(4); | |
201 | z80_bus_cmd(Release); | |
202 | } | |
203 | z80_bus_cmd(Reset); | |
204 | z80_bus_cmd(Request); | |
205 | // z80_write_block(ram_save, 0, cpuinfo_length); | |
206 | z80_bus_cmd(Release); | |
207 | } | |
208 | ||
209 | donot: | |
210 | ||
211 | if (err) | |
212 | cmd_error(CMD_RET_FAILURE, err, NULL); | |
213 | ||
214 | if (done == 0xFF) { | |
215 | if (cputype >= ARRAY_SIZE(cpu_strings)) | |
216 | cputype = 0; | |
217 | printf_P(PSTR("Detected CPU: %S\n"), cpu_strings[cputype]); | |
218 | } | |
219 | ||
220 | return CMD_RET_SUCCESS; | |
221 | } | |
222 | ||
223 | command_ret_t do_cpu_test(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc, char * const argv[]) | |
224 | { | |
225 | ||
226 | uint32_t pulsewidth = 10; /* ms */ | |
227 | ||
228 | int opt; | |
229 | while ((opt = getopt(argc, argv, PSTR("t:"))) != -1) { | |
230 | switch (opt) { | |
231 | case 't': | |
232 | pulsewidth = eval_arg(optarg, NULL); | |
233 | break; | |
234 | default: /* '?' */ | |
235 | return CMD_RET_USAGE; | |
236 | } | |
237 | } | |
238 | ||
239 | if ((z80_bus_state() & ZST_ACQUIRED) != RESET) | |
240 | cmd_error(CMD_RET_FAILURE, ERUNNING, NULL); | |
241 | ||
242 | clear_ctrlc(); /* forget any previous Control C */ | |
243 | do { | |
244 | z80_bus_cmd(Request); | |
245 | test_delay(pulsewidth); | |
246 | z80_bus_cmd(Release); | |
247 | test_delay(pulsewidth); | |
248 | } while (!(had_ctrlc() || ctrlc())); | |
249 | ||
250 | return CMD_RET_SUCCESS; | |
251 | } | |
252 | ||
253 | command_ret_t do_bus_test(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc UNUSED, char * const argv[] UNUSED) | |
254 | { | |
255 | char ch; | |
256 | ||
257 | #if 0 | |
258 | int opt; | |
259 | while ((opt = getopt(argc, argv, PSTR("t:"))) != -1) { | |
260 | switch (opt) { | |
261 | case 't': | |
262 | pulsewidth = eval_arg(optarg, NULL); | |
263 | break; | |
264 | default: /* '?' */ | |
265 | return CMD_RET_USAGE; | |
266 | } | |
267 | } | |
268 | #endif | |
269 | ||
270 | my_puts_P(PSTR( | |
271 | " 1: RESET 4: RUN r: Toggle /RESET\n" | |
272 | " 2: REQUEST 5: RESTART b: Toggle /BUSREQ\n" | |
273 | " 3: RELEASE 6: M_CYCLE\n" | |
274 | "\n" | |
275 | //"Bus state: " | |
276 | )); | |
277 | ||
278 | do { | |
279 | ch = my_getchar(1); | |
280 | if (ch >= 0) { | |
281 | switch (ch) { | |
282 | case '1': /* bus_cmd RESET */ | |
283 | case '2': /* bus_cmd REQUEST */ | |
284 | case '3': /* bus_cmd RELEASE */ | |
285 | case '4': /* bus_cmd RUN */ | |
286 | case '5': /* bus_cmd RESTART */ | |
287 | case '6': /* bus_cmd M_CYCLE */ | |
288 | z80_bus_cmd(ch - '1' + Reset); | |
289 | break; | |
290 | case 'r': /* Toggle RESET */ | |
291 | z80_toggle_reset(); | |
292 | break; | |
293 | case 'b': /* Toggle BUSREQ */ | |
294 | z80_toggle_busreq(); | |
295 | break; | |
296 | } | |
297 | test_delay(10); | |
298 | uint32_t cycles = z80_get_busreq_cycles(); | |
299 | printf_P(PSTR("\rState: %.2x, cycles: %lu, time: %luus "), | |
300 | z80_bus_state(), cycles, (uint32_t) (cycles * 1000000LL / F_CPU)); | |
301 | } | |
302 | } while (ch != 0x03); | |
303 | ||
304 | putchar('\n'); | |
305 | return CMD_RET_SUCCESS; | |
306 | } | |
307 | ||
308 | command_ret_t do_busack_test(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc UNUSED, char * const argv[] UNUSED) | |
309 | { | |
310 | ||
311 | if ((z80_bus_state() & ZST_ACQUIRED) != RESET) | |
312 | cmd_error(CMD_RET_FAILURE, ERUNNING, NULL); | |
313 | ||
314 | z80_bus_cmd(Request); | |
315 | uint32_t result = z80_get_busreq_cycles(); | |
316 | test_delay(20); | |
317 | z80_bus_cmd(Release); | |
318 | ||
319 | #if 0 | |
320 | long div; | |
321 | ||
322 | pinconf = gpio_config_get(pin); | |
323 | if (pinconf == OUTPUT_TIMER) { | |
324 | div = gpio_clockdiv_get(pin); | |
325 | } | |
326 | #endif | |
327 | ||
328 | ||
329 | printf_P(PSTR("cycles: %lu, time: %luus\n"), result, (uint32_t) (result * 1000000LL / F_CPU)); | |
330 | ||
331 | return CMD_RET_SUCCESS; | |
332 | } | |
333 | ||
334 | static const FLASH uint8_t loop_code[] = { | |
335 | /* 0000 */ 0x01,0x36,0x00, /* ld bc,00*256+RCR ; no refresh cycles */ | |
336 | /* 0003 */ 0xAF, /* xor a */ | |
337 | /* 0004 */ 0xED,0x79, /* out (c),a */ | |
338 | /* 0006 */ 0xD3,0x40, /* out (040H),a ; ready */ | |
339 | /* */ /* */ | |
340 | /* */ /* ;Z80 Z180(0W) Z180(MaxW) */ | |
341 | /* 0008 */ /* loop: ;-------------------------- */ | |
342 | /* 0008 */ 0xDB,0x50, /* in a,(050h) ;11 10 +3*3 19 */ | |
343 | /* 000A */ 0xC3,0x08,0x00 /* jp loop ;10 9 +3*3 18 */ | |
344 | /* ;-------------------------- */ | |
345 | /* ;21 19 37 */ | |
346 | }; | |
347 | ||
348 | command_ret_t do_cpu_freq(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc, char * const argv[]) | |
349 | { | |
350 | ||
351 | #define O_SILENT (1<<0) | |
352 | #define O_WENV (1<<1) | |
353 | #define O_LOAD_LOOP (1<<2) | |
354 | #define O_UNLOAD_LOOP (1<<3) | |
355 | ||
356 | uint_fast8_t options = O_LOAD_LOOP | O_UNLOAD_LOOP; | |
357 | uint8_t lcycles = 18; | |
358 | uint16_t timeout = 1000; | |
359 | ||
360 | uint8_t mem_save[ARRAY_SIZE(loop_code)]; | |
361 | ||
362 | int opt; | |
363 | while ((opt = getopt(argc, argv, PSTR("swnuc:t:"))) != -1) { | |
364 | switch (opt) { | |
365 | case 's': | |
366 | options |= O_SILENT; | |
367 | break; | |
368 | case 'w': | |
369 | options |= O_WENV; | |
370 | break; | |
371 | case 'n': | |
372 | options &= ~O_LOAD_LOOP; | |
373 | break; | |
374 | case 'u': | |
375 | options &= ~O_UNLOAD_LOOP; | |
376 | break; | |
377 | case 'c': | |
378 | lcycles = eval_arg(optarg, NULL); | |
379 | break; | |
380 | case 't': | |
381 | timeout = eval_arg(optarg, NULL); | |
382 | break; | |
383 | default: /* '?' */ | |
384 | return CMD_RET_USAGE; | |
385 | } | |
386 | } | |
387 | if (argc - optind != 0) | |
388 | return CMD_RET_USAGE; | |
389 | ||
390 | if (z80_bus_state() & ZST_RUNNING) { | |
391 | if (!(options & O_SILENT)) | |
392 | printf_P(PSTR("Frequency measuring failed. CPU allready running!\n")); | |
393 | return CMD_RET_FAILURE; | |
394 | } | |
395 | ||
396 | ||
397 | z80_bus_cmd(Request); | |
398 | if (options & O_LOAD_LOOP) { | |
399 | z80_read_block(mem_save, 0, ARRAY_SIZE(loop_code)); | |
400 | z80_write_block_P(loop_code, 0, ARRAY_SIZE(loop_code)); | |
401 | } | |
402 | Stat &= ~S_IO_0X40; /* Reset pending int */ | |
403 | z80_bus_cmd(Release); | |
404 | z80_bus_cmd(Run); | |
405 | ||
406 | clear_ctrlc(); /* forget any previous Control C */ | |
407 | ERRNUM err = 0; | |
408 | ||
409 | /* Wait for falling edge */ | |
410 | do { | |
411 | /* check for ctrl-c to abort... */ | |
412 | if (had_ctrlc() || ctrlc()) { | |
413 | err = EINTR; | |
414 | break; | |
415 | } | |
416 | } while ((Stat & S_IO_0X40) == 0); | |
417 | ||
418 | int32_t cpu_freq; | |
419 | if (!err) | |
420 | cpu_freq = z80_measure_phi(lcycles, timeout); | |
421 | ||
422 | z80_bus_cmd(Reset); | |
423 | if (options & O_UNLOAD_LOOP) { | |
424 | z80_bus_cmd(Request); | |
425 | z80_write_block(mem_save, 0, ARRAY_SIZE(loop_code)); | |
426 | z80_bus_cmd(Release); | |
427 | } | |
428 | if (err) | |
429 | cmd_error(CMD_RET_FAILURE, err, NULL); | |
430 | ||
431 | if (!(options & O_SILENT)) { | |
432 | printf_P(PSTR("%ld%S\n"), cpu_freq, cpu_freq < 0 ? PSTR("") : PSTR("Hz")); | |
433 | // if (cpu_freq != 0) | |
434 | // else | |
435 | // printf_P(PSTR("No CPU clock or input frequency to low!\n")); | |
436 | } | |
437 | #if 0 | |
438 | if (options & O_WENV) { | |
439 | if (setenv_ulong(PSTR(ENV_CPU_FREQ), cpu_freq)) { | |
440 | if (!(options & O_SILENT)) | |
441 | printf_P(PSTR("'SETENV (%S, %lu)' failed!\n"), PSTR(ENV_CPU_FREQ), cpu_freq); | |
442 | return CMD_RET_FAILURE; | |
443 | } | |
444 | } | |
445 | #endif | |
446 | return CMD_RET_SUCCESS; | |
447 | } | |
448 | ||
449 | ||
450 | /* | |
451 | * command table for fat subcommands | |
452 | */ | |
453 | ||
454 | cmd_tbl_t cmd_tbl_cpu[] = { | |
455 | CMD_TBL_ITEM( | |
456 | chkcpu, CONFIG_SYS_MAXARGS, CTBL_RPT, do_cpuchk, | |
457 | "Check CPU", | |
458 | "" | |
459 | ), | |
460 | CMD_TBL_ITEM( | |
461 | buscmd, CONFIG_SYS_MAXARGS, CTBL_RPT, do_bus_test, | |
462 | "Bus commands", | |
463 | "" | |
464 | ), | |
465 | CMD_TBL_ITEM( | |
466 | test, CONFIG_SYS_MAXARGS, 1, do_cpu_test, | |
467 | "Do bus request/release cycles", | |
468 | "[-t pulsewidth]" | |
469 | ), | |
470 | CMD_TBL_ITEM( | |
471 | busack, 2, 1, do_busack_test, | |
472 | "Get time from /Reset high to /BUSACK low", | |
473 | "" | |
474 | ), | |
475 | CMD_TBL_ITEM( | |
476 | freq, CONFIG_SYS_MAXARGS, 1, do_cpu_freq, | |
477 | "Measure cpu frequency", | |
478 | "[-qwn] [-c loopcycles] [-t timeout]\n" | |
479 | " -q Be quiet\n" | |
480 | // " -w Write result to environment variable '"ENV_CPU_FREQ"'" | |
481 | ), | |
482 | ||
483 | CMD_TBL_ITEM( | |
484 | help, CONFIG_SYS_MAXARGS, CTBL_RPT, do_help, | |
485 | "Print sub command description/usage", | |
486 | "\n" | |
487 | " - print brief description of all sub commands\n" | |
488 | "fat help command ...\n" | |
489 | " - print detailed usage of sub cmd 'command'" | |
490 | ), | |
491 | ||
492 | /* This does not use the CMD_TBL_ITEM macro as ? can't be used in symbol names */ | |
493 | {FSTR("?"), CONFIG_SYS_MAXARGS, 1, do_help, | |
494 | NULL, | |
495 | #ifdef CONFIG_SYS_LONGHELP | |
496 | FSTR(""), | |
497 | #endif /* CONFIG_SYS_LONGHELP */ | |
498 | NULL, | |
499 | #ifdef CONFIG_AUTO_COMPLETE | |
500 | NULL, | |
501 | #endif | |
502 | }, | |
503 | /* Mark end of table */ | |
504 | CMD_TBL_END(cmd_tbl_cpu) | |
505 | }; | |
506 | ||
507 | ||
508 | command_ret_t do_cpu(cmd_tbl_t *cmdtp UNUSED, uint_fast8_t flag UNUSED, int argc UNUSED, char * const argv[] UNUSED) | |
509 | { | |
510 | //puts_P(PSTR("Huch?")); | |
511 | ||
512 | return CMD_RET_USAGE; | |
513 | } | |
514 | ||
515 | ||
516 | #if 0 /* Z180 Single Step Functions */ | |
517 | /* | |
518 | * Z180 Single Step Functions | |
519 | * | |
520 | */ | |
521 | ||
522 | ||
523 | #define P_RUN PORTG | |
524 | #define RUN 1 | |
525 | #define DDR_RUN DDRG | |
526 | #define P_STEP PORTG | |
527 | #define STEP 0 | |
528 | #define DDR_STEP DDRG | |
529 | #define P_WAIT PORTG | |
530 | #define WAIT 2 | |
531 | #define DDR_WAIT DDRG | |
532 | /* All three signals are on the same Port (PortG) */ | |
533 | #define PORT_SS PORTG | |
534 | #define DDR_SS DDRG | |
535 | #define PIN_SS PING | |
536 | ||
537 | static bool ss_available; | |
538 | ||
539 | int single_step_setup(void) | |
540 | { | |
541 | ss_available = false; | |
542 | ||
543 | #if 0 | |
544 | if (z80_bus_state() & ZST_RUNNING || | |
545 | !(z80_bus_cmd(Request) & ZST_ACQUIRED)) | |
546 | return -1; | |
547 | #endif | |
548 | ||
549 | /* STEP, RUN output, WAIT input */ | |
550 | ||
551 | PORT_SS |= _BV(RUN) | _BV(STEP); | |
552 | DDR_SS |= _BV(RUN) | _BV(STEP); | |
553 | DDR_SS &= ~_BV(WAIT); | |
554 | ||
555 | /* RUN high, MREQ pulse --> WAIT should be low */ | |
556 | z80_mreq_pulse(); | |
557 | ||
558 | if ((PIN_SS & _BV(WAIT)) == 0) { | |
559 | ||
560 | /* RUN high, STEP pulse --> WAIT should be high */ | |
561 | PIN_SS = _BV(STEP); | |
562 | PIN_SS = _BV(STEP); | |
563 | if ((PIN_SS & _BV(WAIT)) != 0) { | |
564 | ||
565 | /* RUN high, MREQ pulse --> WAIT should be low */ | |
566 | z80_mreq_pulse(); | |
567 | if ((PIN_SS & _BV(WAIT)) == 0) { | |
568 | ||
569 | /* RUN low --> WAIT should be high */ | |
570 | PIN_SS = _BV(RUN); | |
571 | if ((PIN_SS & _BV(WAIT)) != 0) { | |
572 | ||
573 | /* RUN low, STEP pulse --> WAIT should be high */ | |
574 | PIN_SS = _BV(STEP); | |
575 | PIN_SS = _BV(STEP); | |
576 | if ((PIN_SS & _BV(WAIT)) != 0) { | |
577 | ||
578 | /* all tests passed */ | |
579 | ss_available = true; | |
580 | } | |
581 | } | |
582 | } | |
583 | } | |
584 | } | |
585 | ||
586 | if (!ss_available) { | |
587 | DDR_SS &= ~(_BV(STEP) | _BV(RUN)); | |
588 | PORT_SS |= _BV(RUN) | _BV(STEP); | |
589 | } | |
590 | ||
591 | return ss_available ? 0 : -1; | |
592 | } | |
593 | #endif |