Hi, my company bought the 68HC705J5 as a replacement of the 68HC705J1 and I'm having problems programming this microcontroller. That this controller is only a OTP of course doesnt make things easier :-(
I'm using the Motorola M68HC705UPGMR Programmer for programming. This programmer loads the .bin file that I transfered to an 27C256 EPROM from that EPROM into the microcontrollers user EPROM. As far as I understood from the programmers manual, the programcode in the EPROM has to begin at the same address as the internal EPROM of the microcontroller does. (which is $300 for this device) - so now the code in my EPROM starts in $300, prior of that address are only FFs. I can load the data into the microcontroller and even verify it - but the microcontroller refuses to work properly. The program-code is the same code that was used for the
68HC705J1, but I of course changed the InterruptVector addresses and the register settings according to the changes that were made between the two processors. I cant see why the code does not work in the "new" processor.Is there someone out there who had a similar problem and can help me to solve it?
Thanks! Tobias