I have a global int variable, and it will be change in ISR
because 8051 is a 8-bit MCU
I have a code if(a == 0) it needs to check lowwer byte= 0 and higher byte =0
but interrupt a--; so if a=0x100 lowwer byte =0 interrupt happen a = 0x0ff higher byte = 0
It will have a wrong result
How ca I do?