I have a minimal development board with a STM8S103F, ST Visual Develop, and ran into the following :
Location zero ($00) is inaccessible using direct adressing modes. Reading returns fixed data, and writing has no effect. Using the debugger it is possible to enter data in the memory section, including location $00.
I tested by patching some opcodes ( 0xB6 ( LD A,$00 ) and 0xB7 ( LD $00,A ) ) that do not function. Reading $00 always returns hex 0x8B in the accumulator and I have no idea why. Any address other than $00 works fine.
