1 /***************************************************************************
2 * Copyright (C) 2006 by Magnus Lundin *
5 * This program is free software; you can redistribute it and/or modify *
6 * it under the terms of the GNU General Public License as published by *
7 * the Free Software Foundation; either version 2 of the License, or *
8 * (at your option) any later version. *
10 * This program is distributed in the hope that it will be useful, *
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13 * GNU General Public License for more details. *
15 * You should have received a copy of the GNU General Public License *
16 * along with this program; if not, write to the *
17 * Free Software Foundation, Inc., *
18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
19 ***************************************************************************/
21 /***************************************************************************
22 There are some things to notice
24 * AT91SAM7S64 is tested
25 * All AT91SAM7Sxx and AT91SAM7Xxx should work but is not tested
26 * All parameters are identified from onchip configuartion registers
28 * The flash controller handles erases automatically on a page (128/265 byte) basis
29 * Only an EraseAll command is supported by the controller
30 * Partial erases can be implemented in software by writing one 0xFFFFFFFF word to
31 * some location in every page in the region to be erased
33 * Lock regions (sectors) are 32 or 64 pages
35 ***************************************************************************/
40 #include "replacements.h"
47 #include "binarybuffer.h"
54 int at91sam7_register_commands(struct command_context_s *cmd_ctx);
55 int at91sam7_flash_bank_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc, struct flash_bank_s *bank);
56 int at91sam7_erase(struct flash_bank_s *bank, int first, int last);
57 int at91sam7_protect(struct flash_bank_s *bank, int set, int first, int last);
58 int at91sam7_write(struct flash_bank_s *bank, u8 *buffer, u32 offset, u32 count);
59 int at91sam7_probe(struct flash_bank_s *bank);
60 int at91sam7_erase_check(struct flash_bank_s *bank);
61 int at91sam7_protect_check(struct flash_bank_s *bank);
62 int at91sam7_info(struct flash_bank_s *bank, char *buf, int buf_size);
64 u32 at91sam7_get_flash_status(flash_bank_t *bank);
65 void at91sam7_set_flash_mode(flash_bank_t *bank,int mode);
66 u32 at91sam7_wait_status_busy(flash_bank_t *bank, u32 waitbits, int timeout);
67 int at91sam7_handle_gpnvm_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
69 flash_driver_t at91sam7_flash =
72 .register_commands = at91sam7_register_commands,
73 .flash_bank_command = at91sam7_flash_bank_command,
74 .erase = at91sam7_erase,
75 .protect = at91sam7_protect,
76 .write = at91sam7_write,
77 .probe = at91sam7_probe,
78 .erase_check = at91sam7_erase_check,
79 .protect_check = at91sam7_protect_check,
84 char * EPROC[8]= {"Unknown","ARM946-E","ARM7TDMI","Unknown","ARM920T","ARM926EJ-S","Unknown","Unknown"};
100 0x200000, /* 2048K */
123 int at91sam7_register_commands(struct command_context_s *cmd_ctx)
125 command_t *at91sam7_cmd = register_command(cmd_ctx, NULL, "at91sam7", NULL, COMMAND_ANY, NULL);
126 register_command(cmd_ctx, at91sam7_cmd, "gpnvm", at91sam7_handle_gpnvm_command, COMMAND_EXEC,
127 "at91sam7 gpnvm <num> <bit> set|clear, set or clear at91sam7 gpnvm bit");
132 u32 at91sam7_get_flash_status(flash_bank_t *bank)
134 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
135 target_t *target = at91sam7_info->target;
138 target_read_u32(target, MC_FSR, &fsr);
143 /** Read clock configuration and set at91sam7_info->usec_clocks*/
144 void at91sam7_read_clock_info(flash_bank_t *bank)
146 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
147 target_t *target = at91sam7_info->target;
148 u32 mckr, mcfr, pllr;
149 unsigned long tmp = 0, mainfreq;
151 /* Read main clock freqency register */
152 target_read_u32(target, CKGR_MCFR, &mcfr);
153 /* Read master clock register */
154 target_read_u32(target, PMC_MCKR, &mckr);
155 /* Read Clock Generator PLL Register */
156 target_read_u32(target, CKGR_PLLR, &pllr);
158 at91sam7_info->mck_valid = 0;
159 switch (mckr & PMC_MCKR_CSS) {
160 case 0: /* Slow Clock */
161 at91sam7_info->mck_valid = 1;
164 case 1: /* Main Clock */
165 if (mcfr & CKGR_MCFR_MAINRDY)
167 at91sam7_info->mck_valid = 1;
168 mainfreq = RC_FREQ / 16ul * (mcfr & 0xffff);
173 case 2: /* Reserved */
175 case 3: /* PLL Clock */
176 if (mcfr & CKGR_MCFR_MAINRDY)
178 target_read_u32(target, CKGR_PLLR, &pllr);
179 if (!(pllr & CKGR_PLLR_DIV))
181 at91sam7_info->mck_valid = 1;
182 mainfreq = RC_FREQ / 16ul * (mcfr & 0xffff);
183 /* Integer arithmetic should have sufficient precision
184 as long as PLL is properly configured. */
185 tmp = mainfreq / (pllr & CKGR_PLLR_DIV) *
186 (((pllr & CKGR_PLLR_MUL) >> 16) + 1);
191 /* Prescaler adjust */
192 if (((mckr & PMC_MCKR_PRES) >> 2) == 7)
193 at91sam7_info->mck_valid = 0;
195 at91sam7_info->mck_freq = tmp >> ((mckr & PMC_MCKR_PRES) >> 2);
197 /* Forget old flash timing */
198 at91sam7_set_flash_mode(bank,FMR_TIMING_NONE);
201 /* Setup the timimg registers for nvbits or normal flash */
202 void at91sam7_set_flash_mode(flash_bank_t *bank,int mode)
204 u32 fmr, fmcn = 0, fws = 0;
205 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
206 target_t *target = at91sam7_info->target;
208 if (mode && (mode != at91sam7_info->flashmode))
210 /* Always round up (ceil) */
211 if (mode==FMR_TIMING_NVBITS)
213 if (at91sam7_info->cidr_arch == 0x60)
215 /* AT91SAM7A3 uses master clocks in 100 ns */
216 fmcn = (at91sam7_info->mck_freq/10000000ul)+1;
220 /* master clocks in 1uS for ARCH 0x7 types */
221 fmcn = (at91sam7_info->mck_freq/1000000ul)+1;
224 else if (mode==FMR_TIMING_FLASH)
225 /* main clocks in 1.5uS */
226 fmcn = (at91sam7_info->mck_freq/666666ul)+1;
228 /* Only allow fmcn=0 if clock period is > 30 us = 33kHz. */
229 if (at91sam7_info->mck_freq <= 33333ul)
231 /* Only allow fws=0 if clock frequency is < 30 MHz. */
232 if (at91sam7_info->mck_freq > 30000000ul)
235 DEBUG("fmcn: %i", fmcn);
236 fmr = fmcn << 16 | fws << 8;
237 target_write_u32(target, MC_FMR, fmr);
240 at91sam7_info->flashmode = mode;
243 u32 at91sam7_wait_status_busy(flash_bank_t *bank, u32 waitbits, int timeout)
247 while ((!((status = at91sam7_get_flash_status(bank)) & waitbits)) && (timeout-- > 0))
249 DEBUG("status: 0x%x", status);
253 DEBUG("status: 0x%x", status);
257 ERROR("status register: 0x%x", status);
259 ERROR("Lock Error Bit Detected, Operation Abort");
261 ERROR("Invalid command and/or bad keyword, Operation Abort");
263 ERROR("Security Bit Set, Operation Abort");
270 /* Send one command to the AT91SAM flash controller */
271 int at91sam7_flash_command(struct flash_bank_s *bank,u8 cmd,u16 pagen)
274 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
275 target_t *target = at91sam7_info->target;
277 fcr = (0x5A<<24) | (pagen<<8) | cmd;
278 target_write_u32(target, MC_FCR, fcr);
279 DEBUG("Flash command: 0x%x, pagenumber:%u", fcr, pagen);
281 if ((at91sam7_info->cidr_arch == 0x60)&&((cmd==SLB)|(cmd==CLB)))
283 /* Lock bit manipulation on AT91SAM7A3 waits for FC_FSR bit 1, EOL */
284 if (at91sam7_wait_status_busy(bank, MC_FSR_EOL, 10)&0x0C)
286 return ERROR_FLASH_OPERATION_FAILED;
291 if (at91sam7_wait_status_busy(bank, MC_FSR_FRDY, 10)&0x0C)
293 return ERROR_FLASH_OPERATION_FAILED;
298 /* Read device id register, main clock frequency register and fill in driver info structure */
299 int at91sam7_read_part_info(struct flash_bank_s *bank)
301 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
302 target_t *target = at91sam7_info->target;
305 if (at91sam7_info->target->state != TARGET_HALTED)
307 return ERROR_TARGET_NOT_HALTED;
310 /* Read and parse chip identification register */
311 target_read_u32(target, DBGU_CIDR, &cidr);
315 WARNING("Cannot identify target as an AT91SAM");
316 return ERROR_FLASH_OPERATION_FAILED;
319 at91sam7_info->cidr = cidr;
320 at91sam7_info->cidr_ext = (cidr>>31)&0x0001;
321 at91sam7_info->cidr_nvptyp = (cidr>>28)&0x0007;
322 at91sam7_info->cidr_arch = (cidr>>20)&0x00FF;
323 at91sam7_info->cidr_sramsiz = (cidr>>16)&0x000F;
324 at91sam7_info->cidr_nvpsiz2 = (cidr>>12)&0x000F;
325 at91sam7_info->cidr_nvpsiz = (cidr>>8)&0x000F;
326 at91sam7_info->cidr_eproc = (cidr>>5)&0x0007;
327 at91sam7_info->cidr_version = cidr&0x001F;
328 bank->size = NVPSIZ[at91sam7_info->cidr_nvpsiz];
329 at91sam7_info->target_name = "Unknown";
331 DEBUG("nvptyp: 0x%3.3x, arch: 0x%4.4x", at91sam7_info->cidr_nvptyp, at91sam7_info->cidr_arch );
333 /* Read main and master clock freqency register */
334 at91sam7_read_clock_info(bank);
336 status = at91sam7_get_flash_status(bank);
337 at91sam7_info->lockbits = status>>16;
338 at91sam7_info->securitybit = (status>>4)&0x01;
340 if (at91sam7_info->cidr_arch == 0x70 )
342 at91sam7_info->num_nvmbits = 2;
343 at91sam7_info->nvmbits = (status>>8)&0x03;
344 bank->base = 0x100000;
346 if (bank->size==0x40000) /* AT91SAM7S256 */
348 at91sam7_info->target_name = "AT91SAM7S256";
349 at91sam7_info->num_lockbits = 16;
350 at91sam7_info->pagesize = 256;
351 at91sam7_info->pages_in_lockregion = 64;
352 at91sam7_info->num_pages = 16*64;
354 if (bank->size==0x20000) /* AT91SAM7S128 */
356 at91sam7_info->target_name = "AT91SAM7S128";
357 at91sam7_info->num_lockbits = 8;
358 at91sam7_info->pagesize = 256;
359 at91sam7_info->pages_in_lockregion = 64;
360 at91sam7_info->num_pages = 8*64;
362 if (bank->size==0x10000) /* AT91SAM7S64 */
364 at91sam7_info->target_name = "AT91SAM7S64";
365 at91sam7_info->num_lockbits = 16;
366 at91sam7_info->pagesize = 128;
367 at91sam7_info->pages_in_lockregion = 32;
368 at91sam7_info->num_pages = 16*32;
370 if (bank->size==0x08000) /* AT91SAM7S321/32 */
372 at91sam7_info->target_name = "AT91SAM7S321/32";
373 at91sam7_info->num_lockbits = 8;
374 at91sam7_info->pagesize = 128;
375 at91sam7_info->pages_in_lockregion = 32;
376 at91sam7_info->num_pages = 8*32;
382 if (at91sam7_info->cidr_arch == 0x71 )
384 at91sam7_info->num_nvmbits = 2;
385 at91sam7_info->nvmbits = (status>>8)&0x03;
386 bank->base = 0x100000;
388 if (bank->size==0x40000) /* AT91SAM7XC256 */
390 at91sam7_info->target_name = "AT91SAM7XC256";
391 at91sam7_info->num_lockbits = 16;
392 at91sam7_info->pagesize = 256;
393 at91sam7_info->pages_in_lockregion = 64;
394 at91sam7_info->num_pages = 16*64;
396 if (bank->size==0x20000) /* AT91SAM7XC128 */
398 at91sam7_info->target_name = "AT91SAM7XC128";
399 at91sam7_info->num_lockbits = 8;
400 at91sam7_info->pagesize = 256;
401 at91sam7_info->pages_in_lockregion = 64;
402 at91sam7_info->num_pages = 8*64;
408 if (at91sam7_info->cidr_arch == 0x72 )
410 at91sam7_info->num_nvmbits = 2;
411 at91sam7_info->nvmbits = (status>>8)&0x03;
412 bank->base = 0x100000;
414 if (bank->size==0x80000) /* AT91SAM7SE512 */
416 at91sam7_info->target_name = "AT91SAM7SE512";
417 at91sam7_info->num_lockbits = 32;
418 at91sam7_info->pagesize = 256;
419 at91sam7_info->pages_in_lockregion = 64;
420 at91sam7_info->num_pages = 32*64;
422 if (bank->size==0x40000)
424 at91sam7_info->target_name = "AT91SAM7SE256";
425 at91sam7_info->num_lockbits = 16;
426 at91sam7_info->pagesize = 256;
427 at91sam7_info->pages_in_lockregion = 64;
428 at91sam7_info->num_pages = 16*64;
430 if (bank->size==0x08000)
432 at91sam7_info->target_name = "AT91SAM7SE32";
433 at91sam7_info->num_lockbits = 8;
434 at91sam7_info->pagesize = 128;
435 at91sam7_info->pages_in_lockregion = 32;
436 at91sam7_info->num_pages = 8*32;
442 if (at91sam7_info->cidr_arch == 0x75 )
444 at91sam7_info->num_nvmbits = 3;
445 at91sam7_info->nvmbits = (status>>8)&0x07;
446 bank->base = 0x100000;
448 if (bank->size==0x40000) /* AT91SAM7X256 */
450 at91sam7_info->target_name = "AT91SAM7X256";
451 at91sam7_info->num_lockbits = 16;
452 at91sam7_info->pagesize = 256;
453 at91sam7_info->pages_in_lockregion = 64;
454 at91sam7_info->num_pages = 16*64;
456 if (bank->size==0x20000) /* AT91SAM7X128 */
458 at91sam7_info->target_name = "AT91SAM7X128";
459 at91sam7_info->num_lockbits = 8;
460 at91sam7_info->pagesize = 256;
461 at91sam7_info->pages_in_lockregion = 64;
462 at91sam7_info->num_pages = 8*64;
468 if (at91sam7_info->cidr_arch == 0x60 )
470 at91sam7_info->num_nvmbits = 3;
471 at91sam7_info->nvmbits = (status>>8)&0x07;
472 bank->base = 0x100000;
475 if (bank->size == 0x40000) /* AT91SAM7A3 */
477 at91sam7_info->target_name = "AT91SAM7A3";
478 at91sam7_info->num_lockbits = 16;
479 at91sam7_info->pagesize = 256;
480 at91sam7_info->pages_in_lockregion = 16;
481 at91sam7_info->num_pages = 16*64;
486 WARNING("at91sam7 flash only tested for AT91SAM7Sxx series");
491 int at91sam7_erase_check(struct flash_bank_s *bank)
493 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
495 if (!at91sam7_info->working_area_size)
505 int at91sam7_protect_check(struct flash_bank_s *bank)
509 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
511 if (at91sam7_info->cidr == 0)
513 at91sam7_read_part_info(bank);
516 if (at91sam7_info->cidr == 0)
518 WARNING("Cannot identify target as an AT91SAM");
519 return ERROR_FLASH_OPERATION_FAILED;
522 status = at91sam7_get_flash_status(bank);
523 at91sam7_info->lockbits = status >> 16;
528 int at91sam7_flash_bank_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc, struct flash_bank_s *bank)
530 at91sam7_flash_bank_t *at91sam7_info;
534 WARNING("incomplete flash_bank at91sam7 configuration");
535 return ERROR_FLASH_BANK_INVALID;
538 at91sam7_info = malloc(sizeof(at91sam7_flash_bank_t));
539 bank->driver_priv = at91sam7_info;
541 at91sam7_info->target = get_target_by_num(strtoul(args[5], NULL, 0));
542 if (!at91sam7_info->target)
544 ERROR("no target '%s' configured", args[5]);
548 /* part wasn't probed for info yet */
549 at91sam7_info->cidr = 0;
554 int at91sam7_erase(struct flash_bank_s *bank, int first, int last)
556 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
558 if (at91sam7_info->target->state != TARGET_HALTED)
560 return ERROR_TARGET_NOT_HALTED;
563 if (at91sam7_info->cidr == 0)
565 at91sam7_read_part_info(bank);
568 if (at91sam7_info->cidr == 0)
570 WARNING("Cannot identify target as an AT91SAM");
571 return ERROR_FLASH_OPERATION_FAILED;
574 if ((first < 0) || (last < first) || (last >= at91sam7_info->num_lockbits))
576 return ERROR_FLASH_SECTOR_INVALID;
579 /* Configure the flash controller timing */
580 at91sam7_read_clock_info(bank);
581 at91sam7_set_flash_mode(bank,FMR_TIMING_FLASH);
583 if ((first == 0) && (last == (at91sam7_info->num_lockbits-1)))
585 return at91sam7_flash_command(bank, EA, 0);
588 WARNING("Can only erase the whole flash area, pages are autoerased on write");
589 return ERROR_FLASH_OPERATION_FAILED;
592 int at91sam7_protect(struct flash_bank_s *bank, int set, int first, int last)
594 u32 cmd, pagen, status;
597 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
599 if (at91sam7_info->target->state != TARGET_HALTED)
601 return ERROR_TARGET_NOT_HALTED;
604 if ((first < 0) || (last < first) || (last >= at91sam7_info->num_lockbits))
606 return ERROR_FLASH_SECTOR_INVALID;
609 if (at91sam7_info->cidr == 0)
611 at91sam7_read_part_info(bank);
614 if (at91sam7_info->cidr == 0)
616 WARNING("Cannot identify target as an AT91SAM");
617 return ERROR_FLASH_OPERATION_FAILED;
620 /* Configure the flash controller timing */
621 at91sam7_read_clock_info(bank);
622 at91sam7_set_flash_mode(bank,FMR_TIMING_NVBITS);
624 for (lockregion=first;lockregion<=last;lockregion++)
626 pagen = lockregion*at91sam7_info->pages_in_lockregion;
631 if (at91sam7_flash_command(bank, cmd, pagen) != ERROR_OK)
633 return ERROR_FLASH_OPERATION_FAILED;
637 status = at91sam7_get_flash_status(bank);
638 at91sam7_info->lockbits = status>>16;
644 int at91sam7_write(struct flash_bank_s *bank, u8 *buffer, u32 offset, u32 count)
646 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
647 target_t *target = at91sam7_info->target;
648 u32 dst_min_alignment, wcount, bytes_remaining = count;
649 u32 first_page, last_page, pagen, buffer_pos;
651 if (at91sam7_info->target->state != TARGET_HALTED)
653 return ERROR_TARGET_NOT_HALTED;
656 if (at91sam7_info->cidr == 0)
658 at91sam7_read_part_info(bank);
661 if (at91sam7_info->cidr == 0)
663 WARNING("Cannot identify target as an AT91SAM");
664 return ERROR_FLASH_OPERATION_FAILED;
667 if (offset + count > bank->size)
668 return ERROR_FLASH_DST_OUT_OF_BANK;
670 dst_min_alignment = at91sam7_info->pagesize;
672 if (offset % dst_min_alignment)
674 WARNING("offset 0x%x breaks required alignment 0x%x", offset, dst_min_alignment);
675 return ERROR_FLASH_DST_BREAKS_ALIGNMENT;
678 if (offset + count > bank->size)
679 return ERROR_FLASH_DST_OUT_OF_BANK;
681 if (at91sam7_info->cidr_arch == 0)
682 return ERROR_FLASH_BANK_NOT_PROBED;
684 first_page = offset/dst_min_alignment;
685 last_page = CEIL(offset + count, dst_min_alignment);
687 DEBUG("first_page: %i, last_page: %i, count %i", first_page, last_page, count);
689 /* Configure the flash controller timing */
690 at91sam7_read_clock_info(bank);
691 at91sam7_set_flash_mode(bank,FMR_TIMING_FLASH);
693 for (pagen=first_page; pagen<last_page; pagen++) {
694 if (bytes_remaining<dst_min_alignment)
695 count = bytes_remaining;
697 count = dst_min_alignment;
698 bytes_remaining -= count;
700 /* Write one block to the PageWriteBuffer */
701 buffer_pos = (pagen-first_page)*dst_min_alignment;
702 wcount = CEIL(count,4);
703 target->type->write_memory(target, bank->base, 4, wcount, buffer+buffer_pos);
705 /* Send Write Page command to Flash Controller */
706 if (at91sam7_flash_command(bank, WP, pagen) != ERROR_OK)
708 return ERROR_FLASH_OPERATION_FAILED;
710 DEBUG("Write page number:%i", pagen);
717 int at91sam7_probe(struct flash_bank_s *bank)
719 /* we can't probe on an at91sam7
720 * if this is an at91sam7, it has the configured flash
722 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
724 if (at91sam7_info->cidr == 0)
726 at91sam7_read_part_info(bank);
729 if (at91sam7_info->cidr == 0)
731 WARNING("Cannot identify target as an AT91SAM");
732 return ERROR_FLASH_OPERATION_FAILED;
738 int at91sam7_info(struct flash_bank_s *bank, char *buf, int buf_size)
741 at91sam7_flash_bank_t *at91sam7_info = bank->driver_priv;
743 at91sam7_read_part_info(bank);
745 if (at91sam7_info->cidr == 0)
747 printed = snprintf(buf, buf_size, "Cannot identify target as an AT91SAM\n");
750 return ERROR_FLASH_OPERATION_FAILED;
753 printed = snprintf(buf, buf_size, "\nat91sam7 information: Chip is %s\n",at91sam7_info->target_name);
757 printed = snprintf(buf, buf_size, "cidr: 0x%8.8x, arch: 0x%4.4x, eproc: %s, version:0x%3.3x, flashsize: 0x%8.8x\n", at91sam7_info->cidr, at91sam7_info->cidr_arch, EPROC[at91sam7_info->cidr_eproc], at91sam7_info->cidr_version, bank->size);
761 printed = snprintf(buf, buf_size, "master clock(estimated): %ikHz \n", at91sam7_info->mck_freq / 1000);
765 if (at91sam7_info->num_lockbits>0) {
766 printed = snprintf(buf, buf_size, "pagesize: %i, lockbits: %i 0x%4.4x, pages in lock region: %i \n", at91sam7_info->pagesize, at91sam7_info->num_lockbits, at91sam7_info->lockbits,at91sam7_info->num_pages/at91sam7_info->num_lockbits);
771 printed = snprintf(buf, buf_size, "securitybit: %i, nvmbits: 0x%1.1x\n", at91sam7_info->securitybit, at91sam7_info->nvmbits);
779 * On AT91SAM7S: When the gpnmv bits are set with
780 * > at91sam7 gpnvm 0 bitnr set
781 * the changes are not visible in the flash controller status register MC_FSR
782 * until the processor has been reset.
783 * On the Olimex board this requires a power cycle.
784 * Note that the AT91SAM7S has the following errata (doc6175.pdf sec 14.1.3):
785 * The maximum number of write/erase cycles for Non Volatile Memory bits is 100. This includes
786 * Lock Bits (LOCKx), General Purpose NVM bits (GPNVMx) and the Security Bit.
788 int at91sam7_handle_gpnvm_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
795 at91sam7_flash_bank_t *at91sam7_info;
799 command_print(cmd_ctx, "at91sam7 gpnvm <num> <bit> <set|clear>");
803 bank = get_flash_bank_by_num(strtoul(args[0], NULL, 0));
809 command_print(cmd_ctx, "flash bank '#%s' is out of bounds", args[0]);
813 at91sam7_info = bank->driver_priv;
815 if (at91sam7_info->target->state != TARGET_HALTED)
817 return ERROR_TARGET_NOT_HALTED;
820 if (at91sam7_info->cidr == 0)
822 at91sam7_read_part_info(bank);
825 if (at91sam7_info->cidr == 0)
827 WARNING("Cannot identify target as an AT91SAM");
828 return ERROR_FLASH_OPERATION_FAILED;
831 if ((bit<0) || (at91sam7_info->num_nvmbits <= bit))
833 command_print(cmd_ctx, "gpnvm bit '#%s' is out of bounds for target %s", args[1],at91sam7_info->target_name);
837 if (strcmp(value, "set") == 0)
841 else if (strcmp(value, "clear") == 0)
847 command_print(cmd_ctx, "usage: at91sam7 gpnvm <num> <bit> <set|clear>");
851 /* Configure the flash controller timing */
852 at91sam7_read_clock_info(bank);
853 at91sam7_set_flash_mode(bank,FMR_TIMING_NVBITS);
855 if (at91sam7_flash_command(bank, flashcmd, (u16)(bit)) != ERROR_OK)
857 return ERROR_FLASH_OPERATION_FAILED;
860 status = at91sam7_get_flash_status(bank);
861 DEBUG("at91sam7_handle_gpnvm_command: cmd 0x%x, value 0x%x, status 0x%x \n",flashcmd,bit,status);
862 at91sam7_info->nvmbits = (status>>8)&((1<<at91sam7_info->num_nvmbits)-1);