Hello, i'm working with a custom board with a STM32L151RD and a st-linkv2. For debugging purpose i only have access to SWD pins: SWCLK (PA14) SWDIO (PA13) TRACESWO (PB3) NRST
But the microcontroller is JTAG wired by default, so my question is: When i select the SWD protocol on the ST-linkv2 it automatically send the special sequence on the SWDIOTMS pin is used to switch between JTAG-DP and SW-DP?
Explanation from the reference manual:
29.3.1 Mechanism to select the JTAG-DP or the SW-DP By default, the JTAG-Debug Port is active. If the debugger host wants to switch to the SW-DP, it must provide a dedicated JTAG sequence on TMS/TCK (respectively mapped to SWDIO and SWCLK) which disables the JTAG-DP and enables the SW-DP. This way it is possible to activate the SWDP using only the SWCLK and SWDIO pins. This sequence is: 1. Send more than 50 TCK cycles with TMS (SWDIO) =1 2. Send the 16-bit sequence on TMS (SWDIO) = 0111100111100111 (MSB transmitted first) 3. Send more than 50 TCK cycles with TMS (SWDIO) =1
Regards
Note that the ST-link is an ST product (the clue is in the name) - it is not a Keil product. Therefore, you'd probably be better asking ST...
Ok, But you have the most visited ARM microcontroller related forum, and there is a chance that someone will actually help me with my problem. But thanks anyway for your answer Regards..