1997 Apr 02

9

Philips Semiconductors

Product specification

2048

interface

PCF85116-3

8.5

Read operations

Read operations are initiated in the same manner as write

operations with the exception that the LSB of the slave

address (R/W) is set to logic 1. There are three basic read

operations; current address read, random read and

sequential read.

8.5.1

During read operations all bits of the memory address are

incremented after each transmission of a data byte.

Contrary to write operations an overflow of the memory

address occurs from 2047 to 0 (see Fig.3).

Fig.7 Master reads PCx85116-3 slave after setting word address (write word address; read data).

handbook, full pagewidth

S

0 A

WORD ADDRESS

A

A

acknowledge

from slave

acknowledge

from slave

acknowledge

from slave

acknowledge

from master

A

DATA

auto increment

word address

MBH928

P

no acknowledge

from master

1

DATA

auto increment

word address

last byte

R/W

S1

n bytes

at this moment master

transmitter becomes

master receiver and

EEPROM slave receiver

becomes slave transmitter

B

B

B

B

B

B

SLAVE ADDRESS

R/W

SLAVE ADDRESS

Fig.8 Master reads PCx85116-3 immediately after first byte (read mode).

handbook, full pagewidth

S

1A

DATA

A1

DATA

acknowledge

from slave

acknowledge

from master

no acknowledge

from master

auto increment

word address

MBH929

auto increment

word address

n bytes

last bytes

P

B

B

B

SLAVE ADDRESS

R/W