however, the eveil is usually in the details. Just an example: the 'V51RD2 has an "internal-external" RAM which is enabled by default, so all MOVX below 0x2FF will go from/to that memory rather than any attached external memory or other memory-mapped device. As we don't know your particular hardware, we cannot judge which of the differences might be significant.

You still might want to go through the initial steps. Get a fresh chip, don't erase the bootloader (don't perform chiperase) - the application FLASH block (block 0) should be erased from factory. Write some very simple, rudimentary program such as blinking a LED, program it into block 0, and try.

You then can go step by step to eliminate any other possible sources of error.

JW