8. cc_rtt_segger

8.1. Communication Channel Via segger j-link

module

cc_rtt_segger

synopsis

channel used to enable RTT communication using Segger J-Link debugger. Additionally, RTT logs can be captured by setting the rtt_log_path parameter on the specified channel.

class pykiso.lib.connectors.cc_rtt_segger.CCRttSegger(serial_number=None, chip_name='STM32L562QE', speed=4000, block_address=537131008, verbose=False, tx_buffer_idx=3, rx_buffer_idx=0, rtt_log_path=None, rtt_log_buffer_idx=0, rtt_log_speed=1000, connection_timeout=5, **kwargs)

Channel using RTT to communicate through Segger J-Link debugger.

Initialize attributes.

Parameters

• serial_number (Optional[int]) – optional segger debugger serial number (required if many connected)

• chip_name (str) – microcontoller name (STM….)

• speed (int) – communication speed in Hz

• block_address (int) – start address to start RTT communication

• tx_buffer_idx (int) – buffer index used for transmission

• rx_buffer_idx (int) – buffer index used for reception

• verbose (bool) – boolean indicating if J-Link connection should be verbose in logging

• rtt_log_path (Optional[str]) – path to the folder where the RTT log file should be stored

• rtt_log_buffer_idx (int) – buffer index used for RTT logging

• rtt_log_speed (float) – number of log per second to be pulled (manage the CPU load for logging) None value fetch log at the CPU’s speed. Default 1000 logs/s

• connection_timeout (int) – available time (in seconds) to open the connection

_cc_close()

Close current RTT communication in use.

Return type

None

_cc_open()

Connect debugger/microcontroller.

This method proceed to the following actions : - create a JLink class instance - connect to the debugger(using open method) - set debugger interface to SWD - connect debugger to the specified chip - start RTT communication - start RTT Logging the specified channel if activated

Raises

JLinkRTTException – if connection timeout occurred.

Return type

None

_cc_receive(timeout=0.1, raw=False)

Read message from the corresponding RTT buffer.

Parameters

• timeout (float) – timeout applied on receive event

• raw (bool) – if raw is True return raw bytes, otherwise Message type like

Return type

Dict[str, Union[Message, bytes, None]]

Returns

Message or raw bytes if successful, otherwise None

_cc_send(msg, raw=False)

Send message using the corresponding RTT buffer.

Parameters

• msg (Message) – message to send, should be Message type or bytes.

• raw (bool) – if raw is True simply send it as it is, otherwise apply serialization

Return type

None

read_target_memory(addr, num_units, zone=None, nbits=32)

Read the given target’s memory units and the given address.

Note

The optional zone specifies a memory zone to access to read from, e.g. IDATA, DDATA, or CODE.

Warning

The given number of bits, if provided, must be either 8, 16, or 32. If not provided, always reads 32 bits.

Parameters

• addr (int) – start address to read from

• num_units (int) – number of units to read

• zone (Optional[str]) – optional memory zone name to access

• nbits (int) – number of bits to use for each unit

Return type

Optional[list]

Returns

List of units read from the target.

receive_log()

Receive RTT log messages from the corresponding RTT buffer.

Return type

None

reset_target(wait_time=100, halt=False)

Reset target via JLink.

Parameters

• wait_time (int) – Amount of milliseconds to delay after reset

• halt (bool) – if the CPU should halt after reset

Return type

None

pykiso.lib.connectors.cc_rtt_segger._need_connection(f)

Decorator to check the JLink is connected and raises an error otherwise

pykiso.lib.connectors.cc_rtt_segger._need_rtt(f)

Decorator to check that a RTT connection has been configured and raises an error otherwise