I have limited knowledge on this topic(MCUs, communication protocols, etc.). I back then worked with an STM32 MCU and did some UART(or USART, can't remember) communication between a PC and the MCU. While I was doing that, I was using on-board ST-LINK programmer/debugger to load my programs into the MCU(F4 Discovery board, to be specific).
Now, while I was doing U(S)ART, I had to configure corresponding pins as U(S)ART alternate function along with configuring U(S)ART peripheral registers.
I recently, looking for programming so called Blue Pill board based on STM32F103Cxx MCU. The point I did not understand is, they(the tutorial owners) don't do a configuration for U(S)ART or so. Generally, they just replace a jumper from one location to another and be able to load programs via USB to TTL converters.
So, what is the exact working behind this, why don't they need to set some pins as U(S)ART Rx or Tx for example?
Another little question, I see some products sold as "FTDI programmer". Now, I do have a Prolific USB to TTL/Serial converter. Will there be a difference in functionality, can I use any USB to TTL converter for programming the MCU? I mean, does that "programmer" have a meaning, or just a naming?