Hi All, When I using debug mode in Keil C,I has a problem: MOV DPH,#0x80 MOV R0,#0x10 MOV A,#0x88 MOVX @R0,A THIS PROGRAM MEANS MOVE DATA 0x88 TO EXTERNAL MEMORY ADDRESS 0x8010, BUT WHY I CAN'T SEE THE CURRENT VALUE IN MEMORY WINDOW,It's my problem or it's a debug mode limit ? Thanks for your help.
The upper address byte comes from P2 (typically) and not from DPH. That's the problem. The following knowledgebase article explains a little about using PDATA in the C Compiler. Maybe this will be helpful. http://www.keil.com/support/docs/1848.htm Jon
THANKS ,Jon I understand now.