swo.c File Reference

Serial Wire Output (SWO) functions. More...

#include <stdint.h>
#include <stdbool.h>
#include "libjaylink.h"
#include "libjaylink-internal.h"

Functions
int	jaylink_swo_start (struct jaylink_device_handle *devh, enum jaylink_swo_mode mode, uint32_t baudrate, uint32_t size)
	Start SWO capture. More...
int	jaylink_swo_stop (struct jaylink_device_handle *devh)
	Stop SWO capture. More...
int	jaylink_swo_read (struct jaylink_device_handle *devh, uint8_t *buffer, uint32_t *length)
	Read SWO trace data. More...
int	jaylink_swo_get_speeds (struct jaylink_device_handle *devh, enum jaylink_swo_mode mode, struct jaylink_swo_speed *speed)
	Retrieve SWO speeds. More...

Detailed Description

Serial Wire Output (SWO) functions.

Function Documentation

int jaylink_swo_get_speeds	(	struct jaylink_device_handle *	devh,
		enum jaylink_swo_mode	mode,
		struct jaylink_swo_speed *	speed
	)

Retrieve SWO speeds.

The speeds are calculated as follows:

speeds = freq / n with n >= min_div and n <= max_div, where n is an integer

Assuming, for example, a base frequency freq of 4500 kHz, a minimum divider min_div of 1 and a maximum divider max_div of 8 then the highest possible SWO speed is 4500 kHz / 1 = 4500 kHz. The next highest speed is 2250 kHz for a divider of 2, and so on. Accordingly, the lowest possible speed is 4500 kHz / 8 = 562.5 kHz.

Note

This function must be used only if the device has the JAYLINK_DEV_CAP_SWO capability.

Parameters

[in,out]	devh	Device handle.
[in]	mode	Capture mode to retrieve speeds for.
[out]	speed	Speed information on success, and undefined on failure.

Return values

JAYLINK_OK	Success.
JAYLINK_ERR_ARG	Invalid arguments.
JAYLINK_ERR_TIMEOUT	A timeout occurred.
JAYLINK_ERR_PROTO	Protocol violation.
JAYLINK_ERR_IO	Input/output error.
JAYLINK_ERR_DEV	Unspecified device error.
JAYLINK_ERR	Other error conditions.

Since

0.1.0

int jaylink_swo_read	(	struct jaylink_device_handle *	devh,
		uint8_t *	buffer,
		uint32_t *	length
	)

Read SWO trace data.

Note

This function must be used only if the device has the JAYLINK_DEV_CAP_SWO capability.

Parameters

[in,out]	devh	Device handle.
[out]	buffer	Buffer to store trace data on success. Its content is undefined on failure.
[in,out]	length	Maximum number of bytes to read. On success, the value gets updated with the actual number of bytes read. The value is undefined on failure.

Return values

JAYLINK_OK	Success.
JAYLINK_ERR_ARG	Invalid arguments.
JAYLINK_ERR_TIMEOUT	A timeout occurred.
JAYLINK_ERR_PROTO	Protocol violation.
JAYLINK_ERR_IO	Input/output error.
JAYLINK_ERR_DEV	Unspecified device error.
JAYLINK_ERR	Other error conditions.

See also

jaylink_swo_start()

Since

0.1.0

int jaylink_swo_start	(	struct jaylink_device_handle *	devh,
		enum jaylink_swo_mode	mode,
		uint32_t	baudrate,
		uint32_t	size
	)

Start SWO capture.

Note

This function must be used only if the device has the JAYLINK_DEV_CAP_SWO capability.

Parameters

[in,out]	devh	Device handle.
[in]	mode	Mode to capture data with.
[in]	baudrate	Baudrate to capture data in bit per second.
[in]	size	Device internal buffer size in bytes to use for capturing.

Return values

JAYLINK_OK	Success.
JAYLINK_ERR_ARG	Invalid arguments.
JAYLINK_ERR_TIMEOUT	A timeout occurred.
JAYLINK_ERR_IO	Input/output error.
JAYLINK_ERR_DEV	Unspecified device error.
JAYLINK_ERR	Other error conditions.

See also

jaylink_swo_get_speeds()

jaylink_get_free_memory()

Since

0.1.0

int jaylink_swo_stop

(

struct jaylink_device_handle *

devh

)

Stop SWO capture.

Note

This function must be used only if the device has the JAYLINK_DEV_CAP_SWO capability.

Parameters

[in,out]

devh

Device handle.

Return values

JAYLINK_OK	Success.
JAYLINK_ERR_ARG	Invalid arguments.
JAYLINK_ERR_TIMEOUT	A timeout occurred.
JAYLINK_ERR_IO	Input/output error.
JAYLINK_ERR_DEV	Unspecified device error.
JAYLINK_ERR	Other error conditions.

See also

jaylink_swo_start()

Since

0.1.0