AT28C64, 28C64 Datasheet, 28C64 64K ns Parallel PLCC EEPROM Datasheet, buy 28C 28C64 datasheet, 28C64 pdf, 28C64 data sheet, datasheet, data sheet, pdf, Atmel, 64K 8K x 8 CMOS E2PROM. 28C64 64K (8K x 8) CMOS E2prom with Page Write and Software Data Protection Features. Fast Read Access Time ns Automatic Page Write Operation.
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Also, I would suggest that you should write a writebyte procedure which sets all address and data wires to output and puts proper values on them, ensures WE and OE are deasserted, asserts CE, asserts and release WE, and releases CE, and a readbyte procedure which sets all address wires to output and puts proper values on them, sets all data wires to input, asserts CE and OE, samples all the data wires, and releases CE and OE.
Any help would be much appreciated. Here is the serial output.
I wrote a program for the Arduino Uno that writes data to the first 4 addresses and then reads the data back. Since I am only using the first three address pins, the rest are tied low. I have tested an earlier version of the above program with a static RAM chip and everything works great.
If it has, you’ll need to wire up all your address wires in order to disable it. Initializing pins for write The timings for this particular EEPROM aren’t super-critical, but it has a timer which starts when the first byte is written and gets reset if another byte is written before it expires. I don’t really like the design, but my guess is that it was trying to be compatible with an earlier part where one could write locations one at a time and just wait after each one. When the timer expires, an internal write cycle is triggered and additional writes before it completes.
28C64A-15 – 28C64A 64K 150ns Parallel EEPROM Technical Data
Post as a guest Name. Sign 2c864 using Facebook. You have not indicated that you are doing anything with them? I’d recommend following that same sequence and also change your write sequence to follow the diagram on the following page. Mar 27 ’13 at I added ms delays between every control pin change and made sure the order was consistent with the datasheet, but still no luck.
28C64 Datasheet PDF
BTW, if the chips are equipment pulls as opposed to new parts, it’s possible that the “software protection” feature has previously been enabled. Home Questions Tags Users Unanswered. That might help things.
(Datasheet) 28C64 pdf – 64K EEPROM (1-page)
Sign up using Email and Password. Looking at the datasheet on page 12 it shows a timing diagram and Chip Enable Access Time can be up to nS. The chips are new, and I actually have two from two different manufacturers. I am using the Xicor 28C64AP chip datasheeet. Here is my code, sorry if it seems too cluttered:.
(Datasheet) 28C64 pdf – 64K CMOS EEPROM (1-page)
That will make the remainder of your code much more readable. I have tied the top 10 address bits low and datadheet only using the first 3 for now. Mar 26 ’13 at Thanks for the info.
Here is my code, sorry if it seems too cluttered: One thing that is missing is on page 7 of the datasheet, it states that you need to write a sequence of codes to disable write-protection. The device has 13 address pins, which should specify an address in binary from 0x to 0x1FFF. All behave the same.
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