Programming the 80C49 microcontroller

[imurillo723]

Does anyone know how to program an 80C49 microcontroller?

Can someone please provide me with a link to an article that shows how to do this?

I have an electronic sign that I would like to use, and it uses an 80C49 controller.

I would just like to dump it's memory so I can find out how the serial input to the sign works (protocol and such).

I already found a few pdf spec sheets on the chip, just need to know how to program or dump the memory.

Appreciate any help on this.

[dobrien]

According to Intel's "8-Bit Embedded Controller Handbook"
Pin EA must be +12v
Pin Data 0 to 7 contains the lower 8 bits of the address bus and the data is read out
while Pin Test 0 is +5v
Pin P20, P21 and P22 contains address A8, A9 and A10
The lower addres bits are latched when the Reset Pin toggled from low to high and
Pin Test 0 is low and the output data is valid after Pin Test 0 is brought high.

Some of Intel's microcontrollers has Lock Bit if this is set it prevents any data
from being read from its memory.

[hkm98]

I think I have an old "emp20" programmer with the appropriate character card
to read/erase/program 8051 family chips in a 40 pin dip socket.
http://www.hkm97.com/Home/index.html

[haklesup]

One would normally use a device programmer of emulator to query the program. A quick search failed to show any obvious tools but if you keep at it, you should find some.

I did see a parallel port based circuit that would excersize the device well enough to read out the contents but although the parts cost would be low, you would still need to write your own code (could be simple in VB ising in and out commands but you still need to push it through yourself.

I see a handfull of the EMP20 programmers suggested by hkm98 on ebay for under $100. you should try to get your hands on a manual and its software before deciding. I doubt thats the only compatible programmer. In a sense that device is pretty generic.