单片机编译错误 error A45: UNDEFINED SYMBOL

MOV A,#FFH
Power.asm(118): error A45: UNDEFINED SYMBOL (PASS-2)

JBC P2.0,CXSM
LJMP CIRCLE
Power.asm(179): error A51: TARGET OUT OF RANGE

Ndiv4: DJNZ B,Ndiv2 提示错误:Power.asm(285): error A45: UNDEFINED SYMBOL (PASS-2)
CLR PSW.5
RET

答：

MOV A,#FFH
后面的16进制数字，不能以字母开头。比如说 ：B5H应该写成： 0B5H。FFH → 0FFH