Programming External EEPROM
When finished with program development you can program your application into EEPROM so it executes automatically when you apply power to the board. The following procedure does this:
1.Make a backup copy of the HELLO.ASM source code.
2.Use a text editor to modify HELLO.ASM. Change the start of the program to $E000 which is the beginning of the EEPROM in U7. Do this by changing the ”ORG $2400” to ”ORG $E000” .
3.Remove the comment * character from before the following lines also:
*LDS #$23FF set the stack pointer
*eloop | nop | endless loop |
*bra eloop
* | org $FFFE | set the reset vector |
*fdb START
4.This will initialize the stack pointer which is necessary when running outside of buffalo but should not be done while running under buffalo since it must handle the stack; cause the program to NOT try to "return" at the end and lastly, program the HC11 reset vector to go to the beginning of the program (the label START) when powered on.
5.
6.Select "Program” and enter your newly assembled HELLO.S19 file if not already there.
7.Make sure External EEPROM is selected in this dialog box then click OK and follow the onscreen instructions (installing the programming jumpers then power off then on or press the RESET switch).
8.When finished programming, remove the jumpers as instructed by the program.
9.Cycle power or press RESET on the board. Your new program should start automatically and the “Hello World” prompt should be displayed in the terminal window.
To return to the buffalo monitor program, repeat the above steps starting with number 6, substituting BUF34X.S19 (in the AxIDE program directory) instead of HELLO.S19. The buffalo monitor should execute again the next time the board is powered on.
7