This was probably copy pasted from the KLxx code, where it was used in the past, also now also has been replaced by a better version. Problem is UART0 runs on core clock, others at the bus clock. So this needs to correctly use the bus clock, where for the K20D50M the bus clock is standard not core clock / 2.
0xc0170
commented
9 years ago
At line 127: http://developer.mbed.org/users/mbed_official/code/mbed-src/file/cc1c4962551c/targets/hal/TARGET_Freescale/TARGET_K20D50M/serial_api.c
uint32_t PCLK = (obj->uart == UART0) ? SystemCoreClock : SystemCoreClock/2;
This was probably copy pasted from the KLxx code, where it was used in the past, also now also has been replaced by a better version. Problem is UART0 runs on core clock, others at the bus clock. So this needs to correctly use the bus clock, where for the K20D50M the bus clock is standard not core clock / 2.
The correct way is here: http://developer.mbed.org/users/mbed_official/code/mbed-src/file/cc1c4962551c/targets/hal/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/serial_api.c