mstechca
New Member
Ok. I bought an 80C51 microprocessor and I bought an AM29F010 128Kb flash ROM.
When I looked at the PDF that supports the ROM, it turns out that more steps are involved with programming the rom.
First I have to send the same unlock code twice, then I set the function code, then the programming address and the data to be sent to that address.
I assume I have to do this for every byte. This is the part the manual does not tell me.
I could make a simple parallel port programmer for the device using latches, counters and flip-flops, but I have a problem, because some of the parts I have are in the 74LS family.
When I tried to make a programmer before (about 6 months ago) for the AT89C2051 chip using the 74LS245, the 74LS245 heated up.
The only flip-flops and latches I have are in the LS series except for these: 2 74HCT245's and 2 74HCT164's.
What I want to know is how could I make the 74LSxxx series IC's flexible to any application without them heating up? Do I need to include resistors?
Is there a limit if I use pull-down or pull-up resistors with them?
I have too many LS series chips I took out of an old computer, and I would rather use them than wait two weeks and pay money for new HC or HCT chips.
Throwing chips in the garbage without a good reason is the worst thing I can do.
When I looked at the PDF that supports the ROM, it turns out that more steps are involved with programming the rom.
First I have to send the same unlock code twice, then I set the function code, then the programming address and the data to be sent to that address.
I assume I have to do this for every byte. This is the part the manual does not tell me.
I could make a simple parallel port programmer for the device using latches, counters and flip-flops, but I have a problem, because some of the parts I have are in the 74LS family.
When I tried to make a programmer before (about 6 months ago) for the AT89C2051 chip using the 74LS245, the 74LS245 heated up.
The only flip-flops and latches I have are in the LS series except for these: 2 74HCT245's and 2 74HCT164's.
What I want to know is how could I make the 74LSxxx series IC's flexible to any application without them heating up? Do I need to include resistors?
Is there a limit if I use pull-down or pull-up resistors with them?
I have too many LS series chips I took out of an old computer, and I would rather use them than wait two weeks and pay money for new HC or HCT chips.
Throwing chips in the garbage without a good reason is the worst thing I can do.
