That might help things. Sign up or log in Sign up using Google. The device has 13 address pins, which should specify an address in binary from 0x to 0x1FFF.
(Datasheet) 28C64 pdf – 64K CMOS EEPROM (1-page)
The same diagram shows CE being asserted followed by OE for a read cycle. Thanks for the dwtasheet. All behave the same. Email Required, but never shown. Here is the serial output. Thanks for the response, supercat.
I wrote a program for the Arduino Uno that writes data to the first 4 addresses and then reads the data back. Sign up using Facebook.
I am using the Xicor 28C64AP chip datasheet. BTW, if the chips are equipment pulls as opposed to new parts, it’s possible that the “software protection” feature has previously been enabled. You have not indicated that you are doing anything with them?
I have edited my question. Sign up using Email and Password. 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.
I have tied the top 10 address bits low and am only using the first 3 for now. I have tested an earlier version of the above program with a static RAM chip and everything works great.
28C64 Datasheet PDF
If it has, you’ll need to wire up all your address wires in order to disable it. Home Questions Tags Users Unanswered.
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, darasheet CE and OE, samples all the data wires, and releases CE and OE.
Mar 26 ’13 at Looking at the datasheet on page 12 it shows a timing diagram daasheet Chip Enable Access Time can be up to nS.
Since I am only using the first three address pins, the rest are tied low. PeterJ 16k 20 42 That will make the remainder of your code much more readable. Here is my code, sorry if it seems too cluttered: I understand the benefits of separating the code into subroutines and will probably do this, but for now I am just trying to get the byte write working.
Any help would be much appreciated. When the timer expires, an internal write cycle is triggered and additional writes before it completes.
The timings for this particular EEPROM aren’t super-critical, but it has a timer which starts datasheft the first byte is written and gets reset if another byte is written before it expires.