jtag_tap.c File Reference

JTAG TAP controller. More...

#include <sys/timer.h>
#include <stdlib.h>
#include <dev/jtag_tap.h>

Include dependency graph for jtag_tap.c:

Data Structures
struct	TEST_MODE_PATH
Functions
JTAG_TAP *	TapOpen (JTAG_CABLE *cable)
	Open a TAP controller instance and assiociate it with a given cable driver.
void	TapClose (JTAG_TAP *tap)
	Release the TAP controller.
void	TapTargetReset (JTAG_TAP *tap, uint32_t us)
	Toggles the target reset line.
void	TapStateWalk (JTAG_TAP *tap, int state)
	Move the TAP controller to the specified state.
void	TapSetIrSize (JTAG_TAP *tap, uint_fast8_t len)
	Set instruction register size.
void	TapData (JTAG_TAP *tap, uint8_t *rbuf, const uint8_t *wbuf, uint32_t len, uint_fast8_t last)
	Read and write data register.
void	TapInstruction (JTAG_TAP *tap, uint32_t code, uint_fast8_t last)
	Store instruction code in instruction register.

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Detailed Description

JTAG TAP controller.

 * $Id$
 * 

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Function Documentation

JTAG_TAP* TapOpen

(

JTAG_CABLE *

cable

)

Open a TAP controller instance and assiociate it with a given cable driver.

Parameters:

Cable

driver structure.

Returns:

Pointer to a TAP controller structure, which must be passed to all other routines.

References JTAG_CABLE::cable_open, calloc, JTAG_UNKNOWN_STATE, NULL, JTAG_TAP::tap_cable, JTAG_TAP::tap_cib, JTAG_TAP::tap_irsize, and JTAG_TAP::tap_state.

void TapClose

(

JTAG_TAP *

tap

)

Release the TAP controller.

Parameters:

tap	Pointer to the TAP controller structure, obtained by a previous call to JtagCable0Open().

References JTAG_CABLE::cable_close, free(), JTAG_TAP::tap_cable, and JTAG_TAP::tap_cib.

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void TapTargetReset	(	JTAG_TAP *	tap,
		uint32_t	us
	)

Toggles the target reset line.

Parameters:

tap	Pointer to the TAP controller structure, obtained by a previous call to JtagCable0Open().
us	Time to keep the reset activated, given in microseconds.

References JTAG_CABLE::cable_reset_target, JTAG_UNKNOWN_STATE, NutMicroDelay(), JTAG_TAP::tap_cable, JTAG_TAP::tap_cib, and JTAG_TAP::tap_state.

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void TapStateWalk	(	JTAG_TAP *	tap,
		int	state
	)

Move the TAP controller to the specified state.

Parameters:

tap	Pointer to the TAP controller structure, obtained by a previous call to JtagCable0Open().
state	Requested state.

References JTAG_CABLE::cable_tms_put, JTAG_TEST_LOGIC_RESET, JTAG_UNKNOWN_STATE, TEST_MODE_PATH::len, TEST_MODE_PATH::seq, JTAG_TAP::tap_cable, JTAG_TAP::tap_cib, and JTAG_TAP::tap_state.

Referenced by TapData(), and TapInstruction().

void TapSetIrSize	(	JTAG_TAP *	tap,
		uint_fast8_t	len
	)

Set instruction register size.

Actually we can determine the size automatically. For now the user must set it by calling this function.

Parameters:

tap	Pointer to the TAP controller structure, obtained by a previous call to JtagCable0Open().
len	Number of bits in the instruction register.

References JTAG_TAP::tap_irsize.

void TapData	(	JTAG_TAP *	tap,
		uint8_t *	rbuf,
		const uint8_t *	wbuf,
		uint32_t	len,
		uint_fast8_t	last
	)

Read and write data register.

Parameters:

tap	Pointer to the TAP controller structure, obtained by a previous call to JtagCable0Open().
rbuf	Points to the buffer that receives the read data. May be NULL if the caller is not interested.
wbuf	Points to the buffer that contains the write data. If NULL, all outgoing bits are zero.
len	Number of bits to read and/or write.
last	Indicates the last data transfer. If set, the TAP controller will move to the Exit1-DR state on the last clock cycle.

References JTAG_CABLE::cable_transfer_data, JTAG_SHIFT_DR, JTAG_TAP::tap_cable, JTAG_TAP::tap_cib, JTAG_TAP::tap_state, and TapStateWalk().

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void TapInstruction	(	JTAG_TAP *	tap,
		uint32_t	code,
		uint_fast8_t	last
	)

Store instruction code in instruction register.

Parameters:

tap	Pointer to the TAP controller structure, obtained by a previous call to JtagCable0Open().
last	Indicates the last data transfer. If set, the TAP controller will move to the Exit1-IR state on the last clock cycle.

References JTAG_CABLE::cable_transfer_data, JTAG_SHIFT_IR, NULL, JTAG_TAP::tap_cable, JTAG_TAP::tap_cib, JTAG_TAP::tap_irsize, JTAG_TAP::tap_state, and TapStateWalk().

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