ACE93C46

Three-wire Serial EEPROM

VER 1.2

6

only at VCC=4.5V to 5.5V

EWDS

1

00

00XXXXX

00XXXX

Disables all programming

instructions

Notes: The X’s in the address field represent don’t care values and must be clocked.

READ (READ):

The Read (READ) instruction contains the address code for the memory location to be read. After the instruction and

address are decoded, data from the selected memory location is available at the serial output pin DO. Output data

changes are synchronized with the rising edges of serial clock SK. It should be noted that a dummy bit (logic “0”)

precedes the 8- or 16-bit data output string.

ERASE/WRITE (EWEN):

To assure data integrity, the part automatically goes into the Erase/Write Disable (EWDS) state when power is first

applied. An Erase/Write Enable(EWEN) instruction must be executed first before any programming instructions can be

carried out. Please note that once in the EWEN state, programming remains enabled until an EWDS instruction is

executed or VCC power is removed from the part.

ERASE (ERASE):

The Erase (ERASE) instruction programs all bits in the specified memory location to the logical “1” state. The

self-timed erase cycle starts once the ERASE instruction and address are decoded. The DO pin outputs the

Ready/Busy status of the part if CS is brought high after being kept low for a minimum of 250 ns (TCS). A logic “1” at pin

DO indicates that the selected memory location has been erased, and the part is ready for another instruction.

WRITE (WRITE):

The Write (WRITE) instruction contains the 8 or 16 bits of data to be written into the specified memory location. The

self-timed programming cycle, tWP, starts after the last bit of data is received at serial data input pin DI. The DO pin

outputs the Ready/Busy status of the part if CS is brought high after being kept low for a minimum of 250 ns (TCS). A

logic “0” at DO indicates that programming is still in progress. A logic “1” indicates that the memory location at the

specified address has been written with the data pattern contained in the instruction and the part is ready for further

instructions. A Ready/Busy status cannot be obtained if the CS is brought high after the end of the selftimed

programming cycle, TWP.

ERASE ALL (ERAL):

The Erase All (ERAL) instruction programs every bit in the memory array to the logic “1” state and is primarily used for

testing purposes. The DO pin outputs the Ready/Busy status of the part if CS is brought high after being kept low for a

minimum of 250 ns (TCS). The ERAL instruction is valid only at VCC = 5.0V ± 10%.

WRITE ALL (WRAL):

The Write All (WRAL) instruction programs all memory locations with the data patterns specified in the instruction.

The DO pin outputs the Ready/Busy status of the part if CS is brought high after being kept low for a minimum of 250ns

(TCS). The WRAL instruction is valid only at VCC = 5.0V ± 10%.