How to change from JTAG-DP to SW-DP (ARM Cortex-M4)

[ANTTI LEINONEN]

Posted on February 17, 2017 at 07:53

Hello, Entering SW-DP mode can be done by following instructions in RM0351 chapter 44.3.1. External TCK/TMS sequence is required.

Is there any other way to change from JTAG-DP to SW-DP? With ARM Cortex-M3 this can be done as described in RM0008 chapter 9.4.2 AF remap and debug I/O configuration register (AFIO_MAPR)

[Mikas Longbardi]

Posted on August 15, 2017 at 02:05

Its annoying for sure and as you mention seams to be a ''tool vendor issue'' since F4/M4 dont have any AFIO_MAPR.

[john doe]

Posted on August 15, 2017 at 04:57

They dont have a MAPR but they do have an AFR. GPIOx->AFR[0], for instance.

GPIOA->AFR[0]:  0x20007701    00100000000000000111011100000001

  PIN  0: TIM2_CH1  PIN  1:  -  PIN  2: USART2_TX  PIN  3: USART2_RX  PIN  4:  -  PIN  5:  -  PIN  6:  -  PIN  7: TIM3_CH2GPIOA->AFR[1]:  0x00000000    00000000000000000000000000000000