Christian Winter

M68EVB912B32 FLASH EEPROM and internal EEPROM

Discussion created by Christian Winter on Mar 30, 2006
Latest reply on Mar 30, 2006 by Christian Winter
I have two questions about the above mentioned board and its FLASH EEPROM and internal EEPROM.

1) I ran out of RAM on this board (only 512 bytes) and wanted to move my code the internal EEPROM (starts at $0D00) while keeping my variables in the RAM (at $800). However, I have encounted the following problem: Whenever I relocate code to the internal EEPROM my programs do not execute D-BUG12 utility subroutines anymore (such as putchar(), getchar(), setuservector() etc.) Why is that?

2) I tried to program the external 32K FLASH EEPROM today without success. I put the board into Bootloader mode and selected "Program". Whenever I select it the board tells me that it could not find Vpf. I follow the instructions in the manual and put header W7 in position 1-2 (move from Vdd to Vpp) and supply 5V and GND to header pin W8, while still keeping 5 V on VDD. However, the boot loader still tells me that Vpf cannot be found. I tested this with 2 boards. The manual says to make sure that you are supplying power according to specifications, and the specifications state that Vpf should be at least Vdd-0.35 V or greater. Hence, since I supply the same to Vdd and Vpp I should be fine. I tried a variable power supply on Vpp and varied between 4.5-5.5 V and still got no results. What else could be wrong on BOTH boards???

Thanks for all and any help on both 1) and 2).