S12VR - Fill Free Memory Space

[carlocurotto]

Hello everybody,

I'm using the tomar microcontroller S12VR for my application.

I need to fill the flash memory not used with NOP and JMP at start up address instructions.

I have modified the .prm file with the FILL directive.

The fill directive required hexadecimal values but I don't know which are the corrispettive values.

I have tested the FILL directive with an example value (0x55) and it is work.

Could you help me?

Thanks in advance

[lama]

Hi,

for mor details please look into https://www.nxp.com/docs/en/reference-manual/S12XCPUV2.pdf 

NOP has machine code 0xA7

JMP  has two different machine codes on the basis of operand:

JMP opr16a                        06 hh ll
JMP oprx0_xysp                 05 xb
JMP oprx9,xysp                  05 xb ff
JMP oprx16,xysp                05 xb ee ff  
JMP [D,xysp]                      05 xb
JMP [oprx16,xysp]              05 xb ee ff

If you want to jump to a direct address, if I understand you well, then you should put there 05 hh ll where hh ll represents address of the function in a non banked memory.

Best regards,

Ladislav