1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
5 * Copyright (C) 2007,2008 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
8 * This program is free software; you can redistribute it and/or modify *
9 * it under the terms of the GNU General Public License as published by *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
13 * This program is distributed in the hope that it will be useful, *
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16 * GNU General Public License for more details. *
18 * You should have received a copy of the GNU General Public License *
19 * along with this program; if not, write to the *
20 * Free Software Foundation, Inc., *
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
22 ***************************************************************************/
26 #include "binarybuffer.h"
30 #ifdef _DEBUG_JTAG_IO_
31 #define DEBUG_JTAG_IO(expr ...) LOG_DEBUG(expr)
33 #define DEBUG_JTAG_IO(expr ...)
36 #ifndef DEBUG_JTAG_IOZ
37 #define DEBUG_JTAG_IOZ 64
40 /*-----<Macros>--------------------------------------------------*/
43 * When given an array, compute its DIMension; in other words, the
44 * number of elements in the array
46 #define DIM(x) (sizeof(x)/sizeof((x)[0]))
48 /** Calculate the number of bytes required to hold @a n TAP scan bits */
49 #define TAP_SCAN_BYTES(n) CEIL(n, 8)
51 /*-----</Macros>-------------------------------------------------*/
54 * Defines JTAG Test Access Port states.
56 * These definitions were gleaned from the ARM7TDMI-S Technical
57 * Reference Manual and validated against several other ARM core
58 * technical manuals. tap_get_tms_path() is sensitive to this numbering
59 * and ordering of the TAP states; furthermore, some interfaces require
60 * specific numbers be used, as they are handed-off directly to their
61 * hardware implementations.
63 typedef enum tap_state
66 /* These are the old numbers. Leave as-is for now... */
67 TAP_RESET = 0, TAP_IDLE = 8,
68 TAP_DRSELECT = 1, TAP_DRCAPTURE = 2, TAP_DRSHIFT = 3, TAP_DREXIT1 = 4,
69 TAP_DRPAUSE = 5, TAP_DREXIT2 = 6, TAP_DRUPDATE = 7,
70 TAP_IRSELECT = 9, TAP_IRCAPTURE = 10, TAP_IRSHIFT = 11, TAP_IREXIT1 = 12,
71 TAP_IRPAUSE = 13, TAP_IREXIT2 = 14, TAP_IRUPDATE = 15,
73 TAP_NUM_STATES = 16, TAP_INVALID = -1,
75 /* Proper ARM recommended numbers */
93 TAP_NUM_STATES = 0x10,
100 * Function tap_state_name
101 * Returns a string suitable for display representing the JTAG tap_state
103 const char* tap_state_name(tap_state_t state);
105 /// The current TAP state of the pending JTAG command queue.
106 extern tap_state_t cmd_queue_cur_state;
109 * This structure defines a single scan field in the scan. It provides
110 * fields for the field's width and pointers to scan input and output
113 * In addition, this structure includes a value and mask that is used by
114 * jtag_add_dr_scan_check() to validate the value that was scanned out.
116 * The allocated, modified, and intmp fields are internal work space.
118 typedef struct scan_field_s
120 /// A pointer to the tap structure to which this field refers.
123 /// The number of bits this field specifies (up to 32)
125 /// A pointer to value to be scanned into the device
127 /// A pointer to a 32-bit memory location for data scanned out
130 /// The value used to check the data scanned out.
131 uint8_t* check_value;
132 /// The mask to go with check_value
135 /// in_value has been allocated for the queue
137 /// Indicates we modified the in_value.
139 /// temporary storage for performing value checks synchronously
143 typedef struct jtag_tap_event_action_s jtag_tap_event_action_t;
145 /* this is really: typedef jtag_tap_t */
146 /* But - the typedef is done in "types.h" */
147 /* due to "forward declaration reasons" */
152 const char* dotted_name;
153 int abs_chain_position;
154 /// Is this TAP disabled after JTAG reset?
155 bool disabled_after_reset;
156 /// Is this TAP currently enabled?
158 int ir_length; /**< size of instruction register */
159 uint32_t ir_capture_value;
160 uint8_t* expected; /**< Capture-IR expected value */
161 uint32_t ir_capture_mask;
162 uint8_t* expected_mask; /**< Capture-IR expected mask */
164 bool hasidcode; /* not all devices have idcode, we'll discover this during chain examination */
165 /**< device identification code */
167 /// Array of expected identification codes */
168 uint32_t* expected_ids;
169 /// Number of expected identification codes
170 uint8_t expected_ids_cnt;
172 /// current instruction
174 /// Bypass register selected
177 jtag_tap_event_action_t *event_action;
179 jtag_tap_t* next_tap;
182 void jtag_tap_init(jtag_tap_t *tap);
183 void jtag_tap_free(jtag_tap_t *tap);
185 extern jtag_tap_t* jtag_all_taps(void);
186 extern const char *jtag_tap_name(const jtag_tap_t *tap);
187 extern jtag_tap_t* jtag_tap_by_string(const char* dotted_name);
188 extern jtag_tap_t* jtag_tap_by_jim_obj(Jim_Interp* interp, Jim_Obj* obj);
189 extern jtag_tap_t* jtag_tap_next_enabled(jtag_tap_t* p);
190 extern unsigned jtag_tap_count_enabled(void);
191 extern unsigned jtag_tap_count(void);
195 * - TRST_ASSERTED triggers two sets of callbacks, after operations to
196 * reset the scan chain -- via TMS+TCK signaling, or deasserting the
197 * nTRST signal -- are queued:
199 * + Callbacks in C code fire first, patching internal state
200 * + Then post-reset event scripts fire ... activating JTAG circuits
201 * via TCK cycles, exiting SWD mode via TMS sequences, etc
203 * During those callbacks, scan chain contents have not been validated.
204 * JTAG operations that address a specific TAP (primarily DR/IR scans)
205 * must *not* be queued.
207 * - TAP_EVENT_SETUP is reported after TRST_ASSERTED, and after the scan
208 * chain has been validated. JTAG operations including scans that
209 * target specific TAPs may be performed.
211 * - TAP_EVENT_ENABLE and TAP_EVENT_DISABLE implement TAP activation and
212 * deactivation outside the core using scripted code that understands
213 * the specific JTAG router type. They might be triggered indirectly
214 * from EVENT_SETUP operations.
218 JTAG_TAP_EVENT_SETUP,
219 JTAG_TAP_EVENT_ENABLE,
220 JTAG_TAP_EVENT_DISABLE,
223 struct jtag_tap_event_action_s
225 enum jtag_event event;
227 jtag_tap_event_action_t* next;
231 * Defines the function signature requide for JTAG event callback
232 * functions, which are added with jtag_register_event_callback()
233 * and removed jtag_unregister_event_callback().
234 * @param event The event to handle.
235 * @param prive A pointer to data that was passed to
236 * jtag_register_event_callback().
237 * @returns Must return ERROR_OK on success, or an error code on failure.
239 * @todo Change to return void or define a use for its return code.
241 typedef int (*jtag_event_handler_t)(enum jtag_event event, void* priv);
243 extern int jtag_register_event_callback(jtag_event_handler_t f, void *x);
244 extern int jtag_unregister_event_callback(jtag_event_handler_t f, void *x);
246 extern int jtag_call_event_callbacks(enum jtag_event event);
249 /// @returns The current JTAG speed setting.
250 int jtag_get_speed(void);
252 * Given a @a speed setting, use the interface @c speed_div callback to
253 * adjust the setting.
254 * @param speed The speed setting to convert back to readable KHz.
255 * @returns ERROR_OK if the interface has not been initialized or on success;
256 * otherwise, the error code produced by the @c speed_div callback.
258 int jtag_get_speed_readable(int *speed);
260 * Set the JTAG speed. This routine will call the underlying
261 * interface @c speed callback, if the interface has been initialized.
262 * @param speed The new speed setting.
263 * @returns ERROR_OK during configuration or on success, or an error
264 * code returned from the interface @c speed callback.
266 int jtag_config_speed(int speed);
269 /// Attempt to configure the interface for the specified KHz.
270 int jtag_config_khz(unsigned khz);
272 * Attempt to enable RTCK/RCLK. If that fails, fallback to the
273 * specified frequency.
275 int jtag_config_rclk(unsigned fallback_speed_khz);
276 /// Retreives the clock speed of the JTAG interface in KHz.
277 unsigned jtag_get_speed_khz(void);
282 RESET_HAS_TRST = 0x1,
283 RESET_HAS_SRST = 0x2,
284 RESET_TRST_AND_SRST = 0x3,
285 RESET_SRST_PULLS_TRST = 0x4,
286 RESET_TRST_PULLS_SRST = 0x8,
287 RESET_TRST_OPEN_DRAIN = 0x10,
288 RESET_SRST_PUSH_PULL = 0x20,
289 RESET_SRST_GATES_JTAG = 0x40,
292 enum reset_types jtag_get_reset_config(void);
293 void jtag_set_reset_config(enum reset_types type);
295 void jtag_set_nsrst_delay(unsigned delay);
296 unsigned jtag_get_nsrst_delay(void);
298 void jtag_set_ntrst_delay(unsigned delay);
299 unsigned jtag_get_ntrst_delay(void);
301 void jtag_set_nsrst_assert_width(unsigned delay);
302 unsigned jtag_get_nsrst_assert_width(void);
304 void jtag_set_ntrst_assert_width(unsigned delay);
305 unsigned jtag_get_ntrst_assert_width(void);
307 /// @returns The current state of TRST.
308 int jtag_get_trst(void);
309 /// @returns The current state of SRST.
310 int jtag_get_srst(void);
312 /// Enable or disable data scan verification checking.
313 void jtag_set_verify(bool enable);
314 /// @returns True if data scan verification will be performed.
315 bool jtag_will_verify(void);
317 /// Enable or disable verification of IR scan checking.
318 void jtag_set_verify_capture_ir(bool enable);
319 /// @returns True if IR scan verification will be performed.
320 bool jtag_will_verify_capture_ir(void);
323 * Initialize interface upon startup. Return a successful no-op upon
324 * subsequent invocations.
326 extern int jtag_interface_init(struct command_context_s* cmd_ctx);
328 /// Shutdown the JTAG interface upon program exit.
329 extern int jtag_interface_quit(void);
332 * Initialize JTAG chain using only a RESET reset. If init fails,
335 extern int jtag_init(struct command_context_s* cmd_ctx);
337 /// reset, then initialize JTAG chain
338 extern int jtag_init_reset(struct command_context_s* cmd_ctx);
339 extern int jtag_register_commands(struct command_context_s* cmd_ctx);
343 * The JTAG interface can be implemented with a software or hardware fifo.
345 * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
346 * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
349 * Code that is relatively insensitive to the path taken through state
350 * machine (as long as it is JTAG compliant) can use @a endstate for
351 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
352 * end state and a subsequent jtag_add_pathmove() must be issued.
356 * Generate an IR SCAN with a list of scan fields with one entry for
359 * If the input field list contains an instruction value for a TAP then
360 * that is used otherwise the TAP is set to bypass.
362 * TAPs for which no fields are passed are marked as bypassed for
363 * subsequent DR SCANs.
366 extern void jtag_add_ir_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
368 * The same as jtag_add_ir_scan except no verification is performed out
371 extern void jtag_add_ir_scan_noverify(int num_fields, const scan_field_t *fields, tap_state_t state);
373 * Duplicate the scan fields passed into the function into an IR SCAN
374 * command. This function assumes that the caller handles extra fields
377 extern void jtag_add_plain_ir_scan(int num_fields, const scan_field_t* fields, tap_state_t endstate);
381 * Set in_value to point to 32 bits of memory to scan into. This
382 * function is a way to handle the case of synchronous and asynchronous
385 * In the event of an asynchronous queue execution the queue buffer
386 * allocation method is used, for the synchronous case the temporary 32
387 * bits come from the input field itself.
389 extern void jtag_alloc_in_value32(scan_field_t *field);
392 * Generate a DR SCAN using the fields passed to the function.
393 * For connected TAPs, the function checks in_fields and uses fields
394 * specified there. For bypassed TAPs, the function generates a dummy
395 * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
397 extern void jtag_add_dr_scan(int num_fields, const scan_field_t* fields, tap_state_t endstate);
398 /// A version of jtag_add_dr_scan() that uses the check_value/mask fields
399 extern void jtag_add_dr_scan_check(int num_fields, scan_field_t* fields, tap_state_t endstate);
401 * Duplicate the scan fields passed into the function into a DR SCAN
402 * command. Unlike jtag_add_dr_scan(), this function assumes that the
403 * caller handles extra fields for bypassed TAPs.
405 extern void jtag_add_plain_dr_scan(int num_fields, const scan_field_t* fields, tap_state_t endstate);
408 * Defines the type of data passed to the jtag_callback_t interface.
409 * The underlying type must allow storing an @c int or pointer type.
411 typedef intptr_t jtag_callback_data_t;
414 * Defines a simple JTAG callback that can allow conversions on data
415 * scanned in from an interface.
417 * This callback should only be used for conversion that cannot fail.
418 * For conversion types or checks that can fail, use the more complete
419 * variant: jtag_callback_t.
421 typedef void (*jtag_callback1_t)(jtag_callback_data_t data0);
423 /// A simpler version of jtag_add_callback4().
424 extern void jtag_add_callback(jtag_callback1_t, jtag_callback_data_t data0);
429 * Defines the interface of the JTAG callback mechanism.
431 * @param in the pointer to the data clocked in
432 * @param data1 An integer big enough to use as an @c int or a pointer.
433 * @param data2 An integer big enough to use as an @c int or a pointer.
434 * @param data3 An integer big enough to use as an @c int or a pointer.
435 * @returns an error code
437 typedef int (*jtag_callback_t)(jtag_callback_data_t data0, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3);
441 * This callback can be executed immediately the queue has been flushed.
443 * The JTAG queue can be executed synchronously or asynchronously.
444 * Typically for USB, the queue is executed asynchronously. For
445 * low-latency interfaces, the queue may be executed synchronously.
447 * The callback mechanism is very general and does not make many
448 * assumptions about what the callback does or what its arguments are.
449 * These callbacks are typically executed *after* the *entire* JTAG
450 * queue has been executed for e.g. USB interfaces, and they are
451 * guaranteeed to be invoked in the order that they were queued.
453 * If the execution of the queue fails before the callbacks, then --
454 * depending on driver implementation -- the callbacks may or may not be
455 * invoked. @todo Can we make this behavior consistent?
457 * The strange name is due to C's lack of overloading using function
460 * @param f The callback function to add.
461 * @param data0 Typically used to point to the data to operate on.
462 * Frequently this will be the data clocked in during a shift operation.
463 * @param data1 An integer big enough to use as an @c int or a pointer.
464 * @param data2 An integer big enough to use as an @c int or a pointer.
465 * @param data3 An integer big enough to use as an @c int or a pointer.
468 extern void jtag_add_callback4(jtag_callback_t f, jtag_callback_data_t data0,
469 jtag_callback_data_t data1, jtag_callback_data_t data2,
470 jtag_callback_data_t data3);
474 * Run a TAP_RESET reset where the end state is TAP_RESET,
475 * regardless of the start state.
477 extern void jtag_add_tlr(void);
480 * Application code *must* assume that interfaces will
481 * implement transitions between states with different
482 * paths and path lengths through the state diagram. The
483 * path will vary across interface and also across versions
484 * of the same interface over time. Even if the OpenOCD code
485 * is unchanged, the actual path taken may vary over time
486 * and versions of interface firmware or PCB revisions.
488 * Use jtag_add_pathmove() when specific transition sequences
491 * Do not use jtag_add_pathmove() unless you need to, but do use it
494 * DANGER! If the target is dependent upon a particular sequence
495 * of transitions for things to work correctly(e.g. as a workaround
496 * for an errata that contradicts the JTAG standard), then pathmove
497 * must be used, even if some jtag interfaces happen to use the
498 * desired path. Worse, the jtag interface used for testing a
499 * particular implementation, could happen to use the "desired"
500 * path when transitioning to/from end
503 * A list of unambigious single clock state transitions, not
504 * all drivers can support this, but it is required for e.g.
505 * XScale and Xilinx support
507 * Note! TAP_RESET must not be used in the path!
509 * Note that the first on the list must be reachable
510 * via a single transition from the current state.
512 * All drivers are required to implement jtag_add_pathmove().
513 * However, if the pathmove sequence can not be precisely
514 * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
515 * must return an error. It is legal, but not recommended, that
516 * a driver returns an error in all cases for a pathmove if it
517 * can only implement a few transitions and therefore
518 * a partial implementation of pathmove would have little practical
521 * If an error occurs, jtag_error will contain one of these error codes:
522 * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
523 * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
524 * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
527 extern void jtag_add_pathmove(int num_states, const tap_state_t* path);
530 * jtag_add_statemove() moves from the current state to @a goal_state.
532 * @param goal_state The final TAP state.
533 * @return ERROR_OK on success, or an error code on failure.
535 * Moves from the current state to the goal \a state.
537 * This needs to be handled according to the xsvf spec, see the XSTATE
538 * command description. From the XSVF spec, pertaining to XSTATE:
540 * For special states known as stable states (Test-Logic-Reset,
541 * Run-Test/Idle, Pause-DR, Pause- IR), an XSVF interpreter follows
542 * predefined TAP state paths when the starting state is a stable state
543 * and when the XSTATE specifies a new stable state. See the STATE
544 * command in the [Ref 5] for the TAP state paths between stable
547 * For non-stable states, XSTATE should specify a state that is only one
548 * TAP state transition distance from the current TAP state to avoid
549 * undefined TAP state paths. A sequence of multiple XSTATE commands can
550 * be issued to transition the TAP through a specific state path.
552 * @note Unless @c tms_bits holds a path that agrees with [Ref 5] in the
553 * above spec, then this code is not fully conformant to the xsvf spec.
554 * This puts a burden on tap_get_tms_path() function from the xsvf spec.
555 * If in doubt, you should confirm that that burden is being met.
557 * Otherwise, @a goal_state must be immediately reachable in one clock
558 * cycle, and does not need to be a stable state.
560 extern int jtag_add_statemove(tap_state_t goal_state);
563 * Goes to TAP_IDLE (if we're not already there), cycle
564 * precisely num_cycles in the TAP_IDLE state, after which move
565 * to @a endstate (unless it is also TAP_IDLE).
567 * @param num_cycles Number of cycles in TAP_IDLE state. This argument
568 * may be 0, in which case this routine will navigate to @a endstate
570 * @param endstate The final state.
572 extern void jtag_add_runtest(int num_cycles, tap_state_t endstate);
575 * A reset of the TAP state machine can be requested.
577 * Whether tms or trst reset is used depends on the capabilities of
578 * the target and jtag interface(reset_config command configures this).
580 * srst can driver a reset of the TAP state machine and vice
583 * Application code may need to examine value of jtag_reset_config
584 * to determine the proper codepath
586 * DANGER! Even though srst drives trst, trst might not be connected to
587 * the interface, and it might actually be *harmful* to assert trst in this case.
589 * This is why combinations such as "reset_config srst_only srst_pulls_trst"
592 * only req_tlr_or_trst and srst can have a transition for a
593 * call as the effects of transitioning both at the "same time"
594 * are undefined, but when srst_pulls_trst or vice versa,
595 * then trst & srst *must* be asserted together.
597 extern void jtag_add_reset(int req_tlr_or_trst, int srst);
601 * Function jtag_set_end_state
603 * Set a global variable to \a state if \a state != TAP_INVALID.
605 * Return the value of the global variable.
608 extern tap_state_t jtag_set_end_state(tap_state_t state);
610 * Function jtag_get_end_state
612 * Return the value of the global variable for end state
615 extern tap_state_t jtag_get_end_state(void);
616 extern void jtag_add_sleep(uint32_t us);
620 * Function jtag_add_stable_clocks
621 * first checks that the state in which the clocks are to be issued is
622 * stable, then queues up clock_count clocks for transmission.
624 void jtag_add_clocks(int num_cycles);
628 * For software FIFO implementations, the queued commands can be executed
629 * during this call or earlier. A sw queue might decide to push out
630 * some of the jtag_add_xxx() operations once the queue is "big enough".
632 * This fn will return an error code if any of the prior jtag_add_xxx()
633 * calls caused a failure, e.g. check failure. Note that it does not
634 * matter if the operation was executed *before* jtag_execute_queue(),
635 * jtag_execute_queue() will still return an error code.
637 * All jtag_add_xxx() calls that have in_handler != NULL will have been
638 * executed when this fn returns, but if what has been queued only
639 * clocks data out, without reading anything back, then JTAG could
640 * be running *after* jtag_execute_queue() returns. The API does
641 * not define a way to flush a hw FIFO that runs *after*
642 * jtag_execute_queue() returns.
644 * jtag_add_xxx() commands can either be executed immediately or
645 * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
647 extern int jtag_execute_queue(void);
649 /// same as jtag_execute_queue() but does not clear the error flag
650 extern void jtag_execute_queue_noclear(void);
652 /// @returns the number of times the scan queue has been flushed
653 int jtag_get_flush_queue_count(void);
655 /// Report Tcl event to all TAPs
656 void jtag_notify_event(enum jtag_event);
659 /* can be implemented by hw + sw */
660 extern int jtag_power_dropout(int* dropout);
661 extern int jtag_srst_asserted(int* srst_asserted);
663 /* JTAG support functions */
666 * Execute jtag queue and check value with an optional mask.
667 * @param field Pointer to scan field.
668 * @param value Pointer to scan value.
669 * @param mask Pointer to scan mask; may be NULL.
670 * @returns Nothing, but calls jtag_set_error() on any error.
672 extern void jtag_check_value_mask(scan_field_t *field, uint8_t *value, uint8_t *mask);
674 extern void jtag_sleep(uint32_t us);
677 * The JTAG subsystem defines a number of error codes,
678 * using codes between -100 and -199.
680 #define ERROR_JTAG_INIT_FAILED (-100)
681 #define ERROR_JTAG_INVALID_INTERFACE (-101)
682 #define ERROR_JTAG_NOT_IMPLEMENTED (-102)
683 #define ERROR_JTAG_TRST_ASSERTED (-103)
684 #define ERROR_JTAG_QUEUE_FAILED (-104)
685 #define ERROR_JTAG_NOT_STABLE_STATE (-105)
686 #define ERROR_JTAG_DEVICE_ERROR (-107)
687 #define ERROR_JTAG_STATE_INVALID (-108)
688 #define ERROR_JTAG_TRANSITION_INVALID (-109)
691 * jtag_add_dr_out() is a version of jtag_add_dr_scan() which
692 * only scans data out. It operates on 32 bit integers instead
693 * of 8 bit, which makes it a better impedance match with
694 * the calling code which often operate on 32 bit integers.
696 * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
698 * num_bits[i] is the number of bits to clock out from value[i] LSB first.
700 * If the device is in bypass, then that is an error condition in
701 * the caller code that is not detected by this fn, whereas
702 * jtag_add_dr_scan() does detect it. Similarly if the device is not in
703 * bypass, data must be passed to it.
705 * If anything fails, then jtag_error will be set and jtag_execute() will
706 * return an error. There is no way to determine if there was a failure
707 * during this function call.
709 * This is an inline fn to speed up embedded hosts. Also note that
710 * interface_jtag_add_dr_out() can be a *small* inline function for
713 * There is no jtag_add_dr_outin() version of this fn that also allows
714 * clocking data back in. Patches gladly accepted!
716 extern void jtag_add_dr_out(jtag_tap_t* tap,
717 int num_fields, const int* num_bits, const uint32_t* value,
718 tap_state_t end_state);
722 * Set the current JTAG core execution error, unless one was set
723 * by a previous call previously. Driver or application code must
724 * use jtag_error_clear to reset jtag_error once this routine has been
725 * called with a non-zero error code.
727 void jtag_set_error(int error);
728 /// @returns The current value of jtag_error
729 int jtag_get_error(void);
731 * Resets jtag_error to ERROR_OK, returning its previous value.
732 * @returns The previous value of @c jtag_error.
734 int jtag_error_clear(void);