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Demo Programs On New Boards

There five programs are loaded into the flash rom memory on every assembled board as part of the testing done by PJRC.

ProgramSource CodeIntel HEX Code
Blink LEDs blink.asm blink.hex
LCD Test lcd_tester.asm lcd_tester.hex
Serial Port Mux Test muxtest.asm muxtest.hex
Erase 4k Flash Block eraseblk.asm eraseblk.hex
Checksum Memory cksum.asm cksum.hex
Download all ten files in one zip file

These assembly language files contain ".org" directives which place the code in Flash ROM, from F000 to F7FF. When you modify these programs, you will need to erase the originals in the Flash ROM before downloading.

Restoring The Board To Original Configuration

If you have erased your flash rom, or accidentally corrupted its contents, or downloaded some program that does not work properly, these steps can be followed to restore the board to the original configuration as shipped by PJRC.

  1. Disconnect power for at least 20 seconds.
  2. Short FLASH ERASE jumper pins
  3. Apply power to the board
  4. Press Enter for baud rate detection
  5. Remove jumper
  6. Download the 5 Intel Hex files to reload the demo programs

These steps will work in all cases. However, in most cases it is sufficient to simply use the "Erase flash rom" ('Z') command, and then download the 5 hex files.

Code Used In 87C52 Internal EPROM

This is the complete monitor code provided on the board:
  • paulmon21.asm - PAULMON 2.1 Configured For This REV 5 Board
  • extra.asm - Disassembler, Memory Editor and Single-Step Utilities
  • pm21_2f4.hex - Intel Hex For 87C52 (these two compiled and merged together)

8051 Development System Circuit Board, Paul Stoffregen
Last updated: February 25, 2005
Status: finished
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