MON390: MOVX CALLED AFTER WR_CODE RETURNS

Information in this article applies to:

• C51 Version 7.05

SYMPTOM

When configuring the MON390 INSTALL.A51 file for writing to code space, the WR_CODE function (shown below) must be modified to match the hardware configuration.

WR_CODE:        MOVX    @DPTR,A
                RET

In most cases, a simple MOVX @DPTR,A is all that is required.

In situations that require customization, the WR_CODE function seems to work fine. However, something seems to overwrite or corrupt code memory.

CAUSE

In versions of MON390 shipped with C51 Version 7.05 and earlier, a MOVX @DPTR, A instruction was invoked directly in the MON390 library. This may cause code memory corruption in some situations.

RESOLUTION

C51 releases Version 7.06a and later include the corrected monitor library. You may download the latest updates from the Keil Website.

SEE ALSO

• MON390: REDIRECTING INTERRUPT VECTORS
• MON390: DOWNLOADING MON390 INTO THE TINI BOARD USING MDK

Last Reviewed: Friday, July 22, 2005