Recently I went into a project to update a portable analyzer firmware. The processor for this project is M68HC705 and its firmware is programmed with its instructions. Although this product has very long service history but we donot want to change more because new generation high level product has been lanched.
currently my task is to understand the code and change some minor display strings, but I am not familiar motolora processor and its system. Does anyone give any suggestion or comments to me? Thanks in advance.
Dear Hao,
I'm quite familiar with this architecture. First of all, have you got the source code? What do you have to start your job? Regards, Celso
Hi Celso,
Thanks for your reply. I have the project assembly source code and get a package of *.exe files. It seems the pakage contains compiler and linker tools, but I have no knowledge on this and have no related documents at this moment.
The first work for this project is to change some strings to the LCD display. So I would like to understand the assembly code, change something, convert to binary and burn it to eeprom.
I download 68HC05 processor instruction tables from NXP.com, but I do not find how to convert them to binary file, how to burn eeprom.
Hi Hao,
As Celso mentioned, we need to know the specific part in order to point you to the correct programmer.
I used the MC68HC705C8 a lot back in the 90's, and I still have the tools. The software packages that you need are (or at least the ones that I used):
pasm05.exe - the assembler
pld.exe - the linker
ubuilds.exe - creates the eprom image from the binary object file
burn.exe (or something similar) - came with the programmer to burn the program into the chip
You would need a programmer, and that is where the correct part number is necessary. The programmer that I have is capable of only programming the C4 and C8 versions of the 705, in either the 40-pin dip or the 44-pin PLCC packages.
The parts came as either windowed (erasable) or one-time-programmable (non-erasable). If you have erasable parts, then you would need a UV eraser as well. Otherwise if you had OTP parts, then you will need new OTP parts, which may be hard to find.
mark
I think it's more comple than you imagine. There are specific tools which are necessary to transfer the binary files to your MCU BTW which is the P/N? If you say E2P it should be HC805xx where xx could be C4 or B6. The P/N will define the tool. So tell us the exact P/N.
Regards,
Celso
Assuming your have the source code, you need a 68HC05 assembler.
An 68HC08 assembler will also work (as it is object code backwards compatible) but be careful not to use any 68HC08 specific instructions.
maybe I will have a lot of questions, but the first is how to comile and link its intruction codes into hex file? could we use any IDE tool?