1997 Nov 21

14

Philips Semiconductors

Product specification

65

× 102 pixels matrix LCD driver

PCF8549

INSTRUCTIONS

The instruction format is divided into two modes: If D/C is set low, the status byte can be read or commands can be sent

to the chip, depending on the R/W signal. If D/C is set high, the DDRAM will be accessed. Every instruction can be sent

in any order to the PCF8549.

Table 1

Instruction set

INSTRUCTION

D/CR/W

COMMAND BYTE

DESCRIPTION

DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0

H=0or1

NOP

0

0

0

0

0

0

0

0

0

0

no operation

Function Set

0

0

0

0

1

MX

MY

PD

V

H

power down control; entry mode;

Extended Instruction Set control (H)

Read Status Byte

0

1

PD

X

X

D

E

MX

MY

X

reads status byte

Write Data

1

0

writes data to RAM

Read Data

1

1

reads data from RAM

H=0

Set Read Modify

Write

0

0

0

0

0

0

0

0

1

RM

sets the read-modify-write mode

Reserved

0

0

0

0

0

0

0

1

X

X

do not use

Display Control

0

0

0

0

0

0

1

D

0

E

sets display configuration

Reserved

0

0

0

0

0

1

X

X

X

X

do not use

Set Y address of

RAM

sets Y-address of RAM: 0

≤ Y ≤ 8

Set X address of

RAM.

sets X-address of RAM: 0

≤ X ≤ 101

H=1

Reserved

0

0

0

0

0

0

0

0

0

1

do not use

Reserved

0

0

0

0

0

0

0

0

1

X

do not use

Temperature Control 0

0

0

0

0

0

0

1

set temperature coefficient (TCx)

Reserved

0

0

0

0

0

0

1

X

X

X

do not use

Bias System

0

0

0

0

0

1

0

Set Bias System(BSx)

Reserved

0

0

0

1

X

X

X

X

X

X

do not use (reserved for test...)