# How is this EEPROM fully addressable?

I am looking at the datasheet for this 64k EEPROM, and I am having trouble understanding how to use it. I would like to do a lookup from a 16-bit address to an 8-bit data word. The chip only has 13 address pins though. It looks like the memory is divided into 8-8K sections, which makes sense,because the 13 address lines can fully address 8K. I don't see any facility, however for switching pages or for giving a full address. How can I get all of the memory from this chip? Do I need to upgrade to something like this 512K model to get a fully 16-bit addressable parallel eeprom?

It's a 64k bits device, i.e. 8k bytes, which needs 13 address lines: $2^{13}$ = 8192 = 8k bytes. The Winbond device is indeed 64k bytes.

Looking at available devices at Mouser I noticed that 64K devices are not that common, and not at all in DIL package. It may be better to use two 32K devices, they seems more common, but still expensive. Maybe your best option is to use Flash. You can find Flash devices at a fraction of the price of an EEPROM, yet having twice the memory capacity. (warning: the example is 5V only.)

• OOps. Capitalization matters. I never pay attention. Jul 26 '11 at 17:42
• Unfortunately, it looks like 512Kb and up parallel eeproms in through-hole packages are not too common anymore. It may be a trick to source these now. Jul 26 '11 at 17:53
• This caught me out once too, where I thought 8K EEPROM was enough to store >1300 bytes. Oops, but luckily it was a serial eeproms for that application. However, I'm afraid you have to parallel them (lots of chips and external logic required) or go for SMD.
– Hans
Jul 26 '11 at 20:10

It is a byte-wide EEPROM. So 64 k bits is 8 kB, which is addressed in 13 bits. There aren't any sections.