stack location within SFR region (0x80 - 0xff)

Hi, from the *.map that I have after compilation, I found that the ?STACK is at 0x82H, within the SFR region. Will the stack overwrites the SFR as it grows?
stack location within SFR region (0x80 - 0xff)

Hi, from the *.map that I have after compilation, I found that the ?STACK is at 0x82H, within the SFR region. Will the stack overwrites the SFR as it grows?
Default 0xFF in unused flash memory (MOV R7,A)

C8051F360 It has recently occured to me that the default instruction 0xFF that exists in all un-used flash memory is not a NOP instruction. I understand that flash memory just works that way...
Default 0xFF in unused flash memory (MOV R7,A)

C8051F360 It has recently occured to me that the default instruction 0xFF that exists in all un-used flash memory is not a NOP instruction. I understand that flash memory just works that way...
a!=b&0xff

unsigned char a=0x12; unsigned char b=0x22; if(a!=b&0xff)//is not true,but why? a = 0; else b = 0;//execute this "a!=b" is true ,so “true &0xff ”should be true,I want to know the c51 compiler why...