CAT64LC40

http://onsemi.com

8

Reset

The RESET pin, when set to HIGH, will reset or abort a

WRITE operation. When RESET is set to HIGH while the

WRITE instruction is being entered, the device will not

execute the WRITE instruction and will keep DO in High−Z

condition.

When RESET is set to HIGH, while the device is in a

clear/write cycle, the device will abort the operation and will

display READY status on the RDY/BSY pin and on the DO

pin if CS is low.

The RESET input affects only the WRITE and

WRITEALL operations. It does not reset any other

operations such as READ, EWEN and EWDS.

Erase/Write Enable and Disable

The CAT64LC40 powers up in the erase/write disabled

state. After power−up or while the device is in an erase/write

disabled state, any write operation must be preceded by an

execution of the EWEN instruction. Once enabled, the

device will stay enabled until an EWDS has been executed

or a power−down has occurred. The EWDS is used to

prevent any inadvertent over−writing of the data. The

EWEN and EWDS instructions have no affect on the READ

operation and are not affected by the RESET input.

Figure 9. EWDS Instruction Timing

SK

DI

CS

DO

RESET

1

HIGH−Z

HIGH

RDY/BUSY

01

0

0

0

0

0