2

3378F–SEEPR–04/04

The AT93C56A/66A is enabled through the Chip Select pin (CS) and accessed via a

3-wire serial interface consisting of Data Input (DI), Data Output (DO), and Shift Clock

(SK). Upon receiving a READ instruction at DI, the address is decoded and the data is

clocked out serially on the data output pin DO. The WRITE cycle is completely self-

timed and no separate ERASE cycle is required before WRITE. The WRITE cycle is

only enabled when the part is in the ERASE/WRITE ENABLE state. When CS is brought

“high” following the initiation of a WRITE cycle, the DO pin outputs the READY/BUSY

status of the part.

The AT93C56A/66A is available in 2.7V to 5.5V and 1.8V to 5.5V versions.

Block Diagram

Note:

When the ORG pin is connected to VCC, the x 16 organization is selected. When it is

connected to ground, the x 8 organization is selected. If the ORG pin is left unconnected

and the application does not load the input beyond the capability of the internal 1 Meg

ohm pullup, then the x 16 organization is selected. The feature is not available on the

1.8V devices.

Absolute Maximum Ratings*

Operating Temperature

......................................−55°C to +125°C

*NOTICE:

Stresses beyond those listed under “Absolute

Maximum Ratings” may cause permanent dam-

age to the device. This is a stress rating only, and

functional operation of the device at these or any

other conditions beyond those indicated in the

operational sections of this specification is not

implied. Exposure to absolute maximum rating

conditions for extended periods may affect

device reliability

Storage Temperature

.........................................−65°C to +150°C

Voltage on Any Pin

with Respect to Ground

........................................ −1.0V to +7.0V

Maximum Operating Voltage .......................................... 6.25V

DC Output Current........................................................ 5.0 mA