A question about F103C8T6 memory map.

[MQi.1]

I found in "Figure 11. Memory map" of "Datasheet - production data for STM32F103x8", the address span between Port A and Port B is 1024(0x4001 0c00 - 0x40010800 = 32*32 bits), while I found in "RM0041 - Reference manual STM32F100xx advanced Arm ® -based 32-bit MCUs", there are only 7 32-bit registers for Port A, and there are not preserved space there, so my question is what is the other 25 32-bit space, are they used for remapping "I/Os alternate function configuration"?

[TDK · Accepted solution]

They're nothing. They either don't exist and/or aren't meant to be used by the user.

Keep in mind you're interacting with registers, not memory. There is no reason that the space needs to be contiguous.