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 ...) \
32 do { if (1) LOG_DEBUG(expr); } while (0)
34 #define DEBUG_JTAG_IO(expr ...) \
35 do { if (0) LOG_DEBUG(expr); } while (0)
38 #ifndef DEBUG_JTAG_IOZ
39 #define DEBUG_JTAG_IOZ 64
42 /*-----<Macros>--------------------------------------------------*/
45 * When given an array, compute its DIMension; in other words, the
46 * number of elements in the array
48 #define DIM(x) (sizeof(x)/sizeof((x)[0]))
50 /** Calculate the number of bytes required to hold @a n TAP scan bits */
51 #define TAP_SCAN_BYTES(n) CEIL(n, 8)
53 /*-----</Macros>-------------------------------------------------*/
56 * Defines JTAG Test Access Port states.
58 * These definitions were gleaned from the ARM7TDMI-S Technical
59 * Reference Manual and validated against several other ARM core
62 * FIXME some interfaces require specific numbers be used, as they
63 * are handed-off directly to their hardware implementations.
64 * Fix those drivers to map as appropriate ... then pick some
65 * sane set of numbers here (where 0/uninitialized == INVALID).
67 typedef enum tap_state
72 /* These are the old numbers. Leave as-is for now... */
73 TAP_RESET = 0, TAP_IDLE = 8,
74 TAP_DRSELECT = 1, TAP_DRCAPTURE = 2, TAP_DRSHIFT = 3, TAP_DREXIT1 = 4,
75 TAP_DRPAUSE = 5, TAP_DREXIT2 = 6, TAP_DRUPDATE = 7,
76 TAP_IRSELECT = 9, TAP_IRCAPTURE = 10, TAP_IRSHIFT = 11, TAP_IREXIT1 = 12,
77 TAP_IRPAUSE = 13, TAP_IREXIT2 = 14, TAP_IRUPDATE = 15,
80 /* Proper ARM recommended numbers */
102 * Function tap_state_name
103 * Returns a string suitable for display representing the JTAG tap_state
105 const char *tap_state_name(tap_state_t state);
107 /// Provides user-friendly name lookup of TAP states.
108 tap_state_t tap_state_by_name(const char *name);
110 /// The current TAP state of the pending JTAG command queue.
111 extern tap_state_t cmd_queue_cur_state;
114 * This structure defines a single scan field in the scan. It provides
115 * fields for the field's width and pointers to scan input and output
118 * In addition, this structure includes a value and mask that is used by
119 * jtag_add_dr_scan_check() to validate the value that was scanned out.
121 * The allocated, modified, and intmp fields are internal work space.
123 typedef struct scan_field_s
125 /// A pointer to the tap structure to which this field refers.
128 /// The number of bits this field specifies (up to 32)
130 /// A pointer to value to be scanned into the device
132 /// A pointer to a 32-bit memory location for data scanned out
135 /// The value used to check the data scanned out.
136 uint8_t* check_value;
137 /// The mask to go with check_value
140 /// in_value has been allocated for the queue
142 /// Indicates we modified the in_value.
144 /// temporary storage for performing value checks synchronously
148 typedef struct jtag_tap_event_action_s jtag_tap_event_action_t;
150 /* this is really: typedef jtag_tap_t */
151 /* But - the typedef is done in "types.h" */
152 /* due to "forward declaration reasons" */
157 const char* dotted_name;
158 int abs_chain_position;
159 /// Is this TAP disabled after JTAG reset?
160 bool disabled_after_reset;
161 /// Is this TAP currently enabled?
163 int ir_length; /**< size of instruction register */
164 uint32_t ir_capture_value;
165 uint8_t* expected; /**< Capture-IR expected value */
166 uint32_t ir_capture_mask;
167 uint8_t* expected_mask; /**< Capture-IR expected mask */
168 uint32_t idcode; /**< device identification code */
169 /** not all devices have idcode,
170 * we'll discover this during chain examination */
173 /// Array of expected identification codes */
174 uint32_t* expected_ids;
175 /// Number of expected identification codes
176 uint8_t expected_ids_cnt;
178 /// current instruction
180 /// Bypass register selected
183 jtag_tap_event_action_t *event_action;
185 jtag_tap_t* next_tap;
188 void jtag_tap_init(jtag_tap_t *tap);
189 void jtag_tap_free(jtag_tap_t *tap);
191 jtag_tap_t* jtag_all_taps(void);
192 const char *jtag_tap_name(const jtag_tap_t *tap);
193 jtag_tap_t* jtag_tap_by_string(const char* dotted_name);
194 jtag_tap_t* jtag_tap_by_jim_obj(Jim_Interp* interp, Jim_Obj* obj);
195 jtag_tap_t* jtag_tap_next_enabled(jtag_tap_t* p);
196 unsigned jtag_tap_count_enabled(void);
197 unsigned jtag_tap_count(void);
201 * - TRST_ASSERTED triggers two sets of callbacks, after operations to
202 * reset the scan chain -- via TMS+TCK signaling, or deasserting the
203 * nTRST signal -- are queued:
205 * + Callbacks in C code fire first, patching internal state
206 * + Then post-reset event scripts fire ... activating JTAG circuits
207 * via TCK cycles, exiting SWD mode via TMS sequences, etc
209 * During those callbacks, scan chain contents have not been validated.
210 * JTAG operations that address a specific TAP (primarily DR/IR scans)
211 * must *not* be queued.
213 * - TAP_EVENT_SETUP is reported after TRST_ASSERTED, and after the scan
214 * chain has been validated. JTAG operations including scans that
215 * target specific TAPs may be performed.
217 * - TAP_EVENT_ENABLE and TAP_EVENT_DISABLE implement TAP activation and
218 * deactivation outside the core using scripted code that understands
219 * the specific JTAG router type. They might be triggered indirectly
220 * from EVENT_SETUP operations.
224 JTAG_TAP_EVENT_SETUP,
225 JTAG_TAP_EVENT_ENABLE,
226 JTAG_TAP_EVENT_DISABLE,
229 struct jtag_tap_event_action_s
231 enum jtag_event event;
233 jtag_tap_event_action_t* next;
237 * Defines the function signature requide for JTAG event callback
238 * functions, which are added with jtag_register_event_callback()
239 * and removed jtag_unregister_event_callback().
240 * @param event The event to handle.
241 * @param prive A pointer to data that was passed to
242 * jtag_register_event_callback().
243 * @returns Must return ERROR_OK on success, or an error code on failure.
245 * @todo Change to return void or define a use for its return code.
247 typedef int (*jtag_event_handler_t)(enum jtag_event event, void* priv);
249 int jtag_register_event_callback(jtag_event_handler_t f, void *x);
250 int jtag_unregister_event_callback(jtag_event_handler_t f, void *x);
252 int jtag_call_event_callbacks(enum jtag_event event);
255 /// @returns The current JTAG speed setting.
256 int jtag_get_speed(void);
258 * Given a @a speed setting, use the interface @c speed_div callback to
259 * adjust the setting.
260 * @param speed The speed setting to convert back to readable KHz.
261 * @returns ERROR_OK if the interface has not been initialized or on success;
262 * otherwise, the error code produced by the @c speed_div callback.
264 int jtag_get_speed_readable(int *speed);
266 * Set the JTAG speed. This routine will call the underlying
267 * interface @c speed callback, if the interface has been initialized.
268 * @param speed The new speed setting.
269 * @returns ERROR_OK during configuration or on success, or an error
270 * code returned from the interface @c speed callback.
272 int jtag_config_speed(int speed);
275 /// Attempt to configure the interface for the specified KHz.
276 int jtag_config_khz(unsigned khz);
278 * Attempt to enable RTCK/RCLK. If that fails, fallback to the
279 * specified frequency.
281 int jtag_config_rclk(unsigned fallback_speed_khz);
282 /// Retreives the clock speed of the JTAG interface in KHz.
283 unsigned jtag_get_speed_khz(void);
288 RESET_HAS_TRST = 0x1,
289 RESET_HAS_SRST = 0x2,
290 RESET_TRST_AND_SRST = 0x3,
291 RESET_SRST_PULLS_TRST = 0x4,
292 RESET_TRST_PULLS_SRST = 0x8,
293 RESET_TRST_OPEN_DRAIN = 0x10,
294 RESET_SRST_PUSH_PULL = 0x20,
295 RESET_SRST_NO_GATING = 0x40,
298 enum reset_types jtag_get_reset_config(void);
299 void jtag_set_reset_config(enum reset_types type);
301 void jtag_set_nsrst_delay(unsigned delay);
302 unsigned jtag_get_nsrst_delay(void);
304 void jtag_set_ntrst_delay(unsigned delay);
305 unsigned jtag_get_ntrst_delay(void);
307 void jtag_set_nsrst_assert_width(unsigned delay);
308 unsigned jtag_get_nsrst_assert_width(void);
310 void jtag_set_ntrst_assert_width(unsigned delay);
311 unsigned jtag_get_ntrst_assert_width(void);
313 /// @returns The current state of TRST.
314 int jtag_get_trst(void);
315 /// @returns The current state of SRST.
316 int jtag_get_srst(void);
318 /// Enable or disable data scan verification checking.
319 void jtag_set_verify(bool enable);
320 /// @returns True if data scan verification will be performed.
321 bool jtag_will_verify(void);
323 /// Enable or disable verification of IR scan checking.
324 void jtag_set_verify_capture_ir(bool enable);
325 /// @returns True if IR scan verification will be performed.
326 bool jtag_will_verify_capture_ir(void);
329 * Initialize interface upon startup. Return a successful no-op upon
330 * subsequent invocations.
332 int jtag_interface_init(struct command_context_s* cmd_ctx);
334 /// Shutdown the JTAG interface upon program exit.
335 int jtag_interface_quit(void);
338 * Initialize JTAG chain using only a RESET reset. If init fails,
341 int jtag_init(struct command_context_s* cmd_ctx);
343 /// reset, then initialize JTAG chain
344 int jtag_init_reset(struct command_context_s* cmd_ctx);
345 int jtag_register_commands(struct command_context_s* cmd_ctx);
346 int jtag_init_inner(struct command_context_s *cmd_ctx);
350 * The JTAG interface can be implemented with a software or hardware fifo.
352 * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
353 * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
356 * Code that is relatively insensitive to the path taken through state
357 * machine (as long as it is JTAG compliant) can use @a endstate for
358 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
359 * end state and a subsequent jtag_add_pathmove() must be issued.
363 * Generate an IR SCAN with a list of scan fields with one entry for
366 * If the input field list contains an instruction value for a TAP then
367 * that is used otherwise the TAP is set to bypass.
369 * TAPs for which no fields are passed are marked as bypassed for
370 * subsequent DR SCANs.
373 void jtag_add_ir_scan(int num_fields,
374 scan_field_t* fields, tap_state_t endstate);
376 * The same as jtag_add_ir_scan except no verification is performed out
379 void jtag_add_ir_scan_noverify(int num_fields,
380 const scan_field_t *fields, tap_state_t state);
382 * Duplicate the scan fields passed into the function into an IR SCAN
383 * command. This function assumes that the caller handles extra fields
386 void jtag_add_plain_ir_scan(int num_fields,
387 const scan_field_t* fields, tap_state_t endstate);
391 * Set in_value to point to 32 bits of memory to scan into. This
392 * function is a way to handle the case of synchronous and asynchronous
395 * In the event of an asynchronous queue execution the queue buffer
396 * allocation method is used, for the synchronous case the temporary 32
397 * bits come from the input field itself.
399 void jtag_alloc_in_value32(scan_field_t *field);
402 * Generate a DR SCAN using the fields passed to the function.
403 * For connected TAPs, the function checks in_fields and uses fields
404 * specified there. For bypassed TAPs, the function generates a dummy
405 * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
407 void jtag_add_dr_scan(int num_fields,
408 const scan_field_t* fields, tap_state_t endstate);
409 /// A version of jtag_add_dr_scan() that uses the check_value/mask fields
410 void jtag_add_dr_scan_check(int num_fields,
411 scan_field_t* fields, tap_state_t endstate);
413 * Duplicate the scan fields passed into the function into a DR SCAN
414 * command. Unlike jtag_add_dr_scan(), this function assumes that the
415 * caller handles extra fields for bypassed TAPs.
417 void jtag_add_plain_dr_scan(int num_fields,
418 const scan_field_t* fields, tap_state_t endstate);
421 * Defines the type of data passed to the jtag_callback_t interface.
422 * The underlying type must allow storing an @c int or pointer type.
424 typedef intptr_t jtag_callback_data_t;
427 * Defines a simple JTAG callback that can allow conversions on data
428 * scanned in from an interface.
430 * This callback should only be used for conversion that cannot fail.
431 * For conversion types or checks that can fail, use the more complete
432 * variant: jtag_callback_t.
434 typedef void (*jtag_callback1_t)(jtag_callback_data_t data0);
436 /// A simpler version of jtag_add_callback4().
437 void jtag_add_callback(jtag_callback1_t, jtag_callback_data_t data0);
442 * Defines the interface of the JTAG callback mechanism.
444 * @param in the pointer to the data clocked in
445 * @param data1 An integer big enough to use as an @c int or a pointer.
446 * @param data2 An integer big enough to use as an @c int or a pointer.
447 * @param data3 An integer big enough to use as an @c int or a pointer.
448 * @returns an error code
450 typedef int (*jtag_callback_t)(jtag_callback_data_t data0,
451 jtag_callback_data_t data1,
452 jtag_callback_data_t data2,
453 jtag_callback_data_t data3);
457 * This callback can be executed immediately the queue has been flushed.
459 * The JTAG queue can be executed synchronously or asynchronously.
460 * Typically for USB, the queue is executed asynchronously. For
461 * low-latency interfaces, the queue may be executed synchronously.
463 * The callback mechanism is very general and does not make many
464 * assumptions about what the callback does or what its arguments are.
465 * These callbacks are typically executed *after* the *entire* JTAG
466 * queue has been executed for e.g. USB interfaces, and they are
467 * guaranteeed to be invoked in the order that they were queued.
469 * If the execution of the queue fails before the callbacks, then --
470 * depending on driver implementation -- the callbacks may or may not be
471 * invoked. @todo Can we make this behavior consistent?
473 * The strange name is due to C's lack of overloading using function
476 * @param f The callback function to add.
477 * @param data0 Typically used to point to the data to operate on.
478 * Frequently this will be the data clocked in during a shift operation.
479 * @param data1 An integer big enough to use as an @c int or a pointer.
480 * @param data2 An integer big enough to use as an @c int or a pointer.
481 * @param data3 An integer big enough to use as an @c int or a pointer.
484 void jtag_add_callback4(jtag_callback_t f, jtag_callback_data_t data0,
485 jtag_callback_data_t data1, jtag_callback_data_t data2,
486 jtag_callback_data_t data3);
490 * Run a TAP_RESET reset where the end state is TAP_RESET,
491 * regardless of the start state.
493 void jtag_add_tlr(void);
496 * Application code *must* assume that interfaces will
497 * implement transitions between states with different
498 * paths and path lengths through the state diagram. The
499 * path will vary across interface and also across versions
500 * of the same interface over time. Even if the OpenOCD code
501 * is unchanged, the actual path taken may vary over time
502 * and versions of interface firmware or PCB revisions.
504 * Use jtag_add_pathmove() when specific transition sequences
507 * Do not use jtag_add_pathmove() unless you need to, but do use it
510 * DANGER! If the target is dependent upon a particular sequence
511 * of transitions for things to work correctly(e.g. as a workaround
512 * for an errata that contradicts the JTAG standard), then pathmove
513 * must be used, even if some jtag interfaces happen to use the
514 * desired path. Worse, the jtag interface used for testing a
515 * particular implementation, could happen to use the "desired"
516 * path when transitioning to/from end
519 * A list of unambigious single clock state transitions, not
520 * all drivers can support this, but it is required for e.g.
521 * XScale and Xilinx support
523 * Note! TAP_RESET must not be used in the path!
525 * Note that the first on the list must be reachable
526 * via a single transition from the current state.
528 * All drivers are required to implement jtag_add_pathmove().
529 * However, if the pathmove sequence can not be precisely
530 * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
531 * must return an error. It is legal, but not recommended, that
532 * a driver returns an error in all cases for a pathmove if it
533 * can only implement a few transitions and therefore
534 * a partial implementation of pathmove would have little practical
537 * If an error occurs, jtag_error will contain one of these error codes:
538 * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
539 * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
540 * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
543 void jtag_add_pathmove(int num_states, const tap_state_t* path);
546 * jtag_add_statemove() moves from the current state to @a goal_state.
548 * @param goal_state The final TAP state.
549 * @return ERROR_OK on success, or an error code on failure.
551 * Moves from the current state to the goal \a state.
552 * Both states must be stable.
554 int jtag_add_statemove(tap_state_t goal_state);
557 * Goes to TAP_IDLE (if we're not already there), cycle
558 * precisely num_cycles in the TAP_IDLE state, after which move
559 * to @a endstate (unless it is also TAP_IDLE).
561 * @param num_cycles Number of cycles in TAP_IDLE state. This argument
562 * may be 0, in which case this routine will navigate to @a endstate
564 * @param endstate The final state.
566 void jtag_add_runtest(int num_cycles, tap_state_t endstate);
569 * A reset of the TAP state machine can be requested.
571 * Whether tms or trst reset is used depends on the capabilities of
572 * the target and jtag interface(reset_config command configures this).
574 * srst can driver a reset of the TAP state machine and vice
577 * Application code may need to examine value of jtag_reset_config
578 * to determine the proper codepath
580 * DANGER! Even though srst drives trst, trst might not be connected to
581 * the interface, and it might actually be *harmful* to assert trst in this case.
583 * This is why combinations such as "reset_config srst_only srst_pulls_trst"
586 * only req_tlr_or_trst and srst can have a transition for a
587 * call as the effects of transitioning both at the "same time"
588 * are undefined, but when srst_pulls_trst or vice versa,
589 * then trst & srst *must* be asserted together.
591 void jtag_add_reset(int req_tlr_or_trst, int srst);
595 * Function jtag_set_end_state
597 * Set a global variable to \a state if \a state != TAP_INVALID.
599 * Return the value of the global variable.
602 tap_state_t jtag_set_end_state(tap_state_t state);
604 * Function jtag_get_end_state
606 * Return the value of the global variable for end state
609 tap_state_t jtag_get_end_state(void);
610 void jtag_add_sleep(uint32_t us);
614 * Function jtag_add_stable_clocks
615 * first checks that the state in which the clocks are to be issued is
616 * stable, then queues up clock_count clocks for transmission.
618 void jtag_add_clocks(int num_cycles);
622 * For software FIFO implementations, the queued commands can be executed
623 * during this call or earlier. A sw queue might decide to push out
624 * some of the jtag_add_xxx() operations once the queue is "big enough".
626 * This fn will return an error code if any of the prior jtag_add_xxx()
627 * calls caused a failure, e.g. check failure. Note that it does not
628 * matter if the operation was executed *before* jtag_execute_queue(),
629 * jtag_execute_queue() will still return an error code.
631 * All jtag_add_xxx() calls that have in_handler != NULL will have been
632 * executed when this fn returns, but if what has been queued only
633 * clocks data out, without reading anything back, then JTAG could
634 * be running *after* jtag_execute_queue() returns. The API does
635 * not define a way to flush a hw FIFO that runs *after*
636 * jtag_execute_queue() returns.
638 * jtag_add_xxx() commands can either be executed immediately or
639 * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
641 int jtag_execute_queue(void);
643 /// same as jtag_execute_queue() but does not clear the error flag
644 void jtag_execute_queue_noclear(void);
646 /// @returns the number of times the scan queue has been flushed
647 int jtag_get_flush_queue_count(void);
649 /// Report Tcl event to all TAPs
650 void jtag_notify_event(enum jtag_event);
653 /* can be implemented by hw + sw */
654 int jtag_power_dropout(int* dropout);
655 int jtag_srst_asserted(int* srst_asserted);
657 /* JTAG support functions */
660 * Execute jtag queue and check value with an optional mask.
661 * @param field Pointer to scan field.
662 * @param value Pointer to scan value.
663 * @param mask Pointer to scan mask; may be NULL.
664 * @returns Nothing, but calls jtag_set_error() on any error.
666 void jtag_check_value_mask(scan_field_t *field, uint8_t *value, uint8_t *mask);
668 void jtag_sleep(uint32_t us);
671 * The JTAG subsystem defines a number of error codes,
672 * using codes between -100 and -199.
674 #define ERROR_JTAG_INIT_FAILED (-100)
675 #define ERROR_JTAG_INVALID_INTERFACE (-101)
676 #define ERROR_JTAG_NOT_IMPLEMENTED (-102)
677 #define ERROR_JTAG_TRST_ASSERTED (-103)
678 #define ERROR_JTAG_QUEUE_FAILED (-104)
679 #define ERROR_JTAG_NOT_STABLE_STATE (-105)
680 #define ERROR_JTAG_DEVICE_ERROR (-107)
681 #define ERROR_JTAG_STATE_INVALID (-108)
682 #define ERROR_JTAG_TRANSITION_INVALID (-109)
683 #define ERROR_JTAG_INIT_SOFT_FAIL (-110)
686 * jtag_add_dr_out() is a version of jtag_add_dr_scan() which
687 * only scans data out. It operates on 32 bit integers instead
688 * of 8 bit, which makes it a better impedance match with
689 * the calling code which often operate on 32 bit integers.
691 * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
693 * num_bits[i] is the number of bits to clock out from value[i] LSB first.
695 * If the device is in bypass, then that is an error condition in
696 * the caller code that is not detected by this fn, whereas
697 * jtag_add_dr_scan() does detect it. Similarly if the device is not in
698 * bypass, data must be passed to it.
700 * If anything fails, then jtag_error will be set and jtag_execute() will
701 * return an error. There is no way to determine if there was a failure
702 * during this function call.
704 * This is an inline fn to speed up embedded hosts. Also note that
705 * interface_jtag_add_dr_out() can be a *small* inline function for
708 * There is no jtag_add_dr_outin() version of this fn that also allows
709 * clocking data back in. Patches gladly accepted!
711 void jtag_add_dr_out(jtag_tap_t* tap,
712 int num_fields, const int* num_bits, const uint32_t* value,
713 tap_state_t end_state);
717 * Set the current JTAG core execution error, unless one was set
718 * by a previous call previously. Driver or application code must
719 * use jtag_error_clear to reset jtag_error once this routine has been
720 * called with a non-zero error code.
722 void jtag_set_error(int error);
723 /// @returns The current value of jtag_error
724 int jtag_get_error(void);
726 * Resets jtag_error to ERROR_OK, returning its previous value.
727 * @returns The previous value of @c jtag_error.
729 int jtag_error_clear(void);
732 * Return true if it's safe for a background polling task to access the
733 * JTAG scan chain. Polling may be explicitly disallowed, and is also
734 * unsafe while nTRST is active or the JTAG clock is gated off.,
736 bool is_jtag_poll_safe(void);
739 * Return flag reporting whether JTAG polling is disallowed.
741 bool jtag_poll_get_enabled(void);
744 * Assign flag reporting whether JTAG polling is disallowed.
746 void jtag_poll_set_enabled(bool value);