mstechca
New Member
ok, It seems that adding external pull-up resistors to the data pins (of the at89c2051 uC) did most of the trick, however, there is a problem with the timing.
The 1st byte is correctly written into the uC, some of the subsequent bytes are not. When I programmed the chip, I made PROG low, made it high, and then I made sure that a positive was applied to the XTAL pin followed by a negative to the XTAL. I made each step take 100ms (which is well over ATMEL's minimums).
I'll try adding a pull-up or a pull-down resistor to the XTAL connection and see if that works.
but if you guys can suggest anything else, let me know. Thanks.
The 1st byte is correctly written into the uC, some of the subsequent bytes are not. When I programmed the chip, I made PROG low, made it high, and then I made sure that a positive was applied to the XTAL pin followed by a negative to the XTAL. I made each step take 100ms (which is well over ATMEL's minimums).
I'll try adding a pull-up or a pull-down resistor to the XTAL connection and see if that works.
but if you guys can suggest anything else, let me know. Thanks.