12/18

M34S32

Figure 11. Write Modes Sequence with WC = 1

and WCpol = 0

Note: 1. The device has the same behavior when WC = 0 and

WCpol = 1.

Read Operations

On delivery, the memory content is set at all “1”s

(or FFh).

Current Address Read. The memory has an in-

ternal address counter. Each time a byte is read,

this counter is incremented. For the Current Ad-

dress Read mode, following a START condition,

the master sends a Device Select Byte with the

RW bit set to 1. The memory acknowledges this

and outputs the byte addressed by the internal ad-

dress counter. This counter is then incremented.

The master does NOT acknowledge the byte out-

put, but terminates the transfer with a STOP con-

dition.

A Current Address Read in the OTP page is per-

formed by sending the appropriate Device Select

Byte, as described in Table 3.

BYTE WRITE

DEV SEL

BYTE ADDR

BYTE ADDR

DATA IN

WC

PAGE WRITE

DEV SEL

BYTE ADDR

BYTE ADDR

DATA IN 1

WC

DATA IN 2

AI01120B

PAGE WRITE

(cont'd)

WC (cont'd)

DATA IN N

ACK

ACK

ACK

NO ACK

R/W

ACK

ACK

ACK

NO ACK

R/W

NO ACK

NO ACK

Let us suppose, again, that byte N of the OTP

page has just been addressed (for example be-

cause of a Write in the OTP page or a Random

read in the OTP page). If the next instruction uses

the Current Address Read Mode of the device, the

first byte read in EEPROM will be in page 0, at ad-

dress N+1 (or page 1, byte 0 if the last OTP byte

addressed was at location 31).

Random Address Read. A dummy write is per-

formed to load the address into the address coun-

ter, see Figure 10. This is followed by another

START condition from the master and the byte ad-

dress repeated with the RW bit set to 1. The mem-

ory acknowledges this and outputs the byte

addressed. The master does NOT acknowledge

the byte output, but terminates the transfer with a

STOP condition.

Specific features of the Random Address read

in the OTP page. This instruction must consist of

the two sequences shown on page 14 (Sequence

A followed by Sequence B).