1999 Aug 16

17

Philips Semiconductors

Product specification

65

× 102 pixels matrix LCD driver

PCF8548

Table 2

Explanations of symbols in Table 1

12.1

External reset (RES)

After power-on a reset pulse must be applied immediately to the chip, as it is in an undefined state. A reset of the chip

can be achieved using the external reset pad. After the reset the LCD driver is set to the following states:

• Power-down mode (PD = 1)

• Horizontal addressing (V = 0)

• Normal instruction set (H = 0)

• Normal display (MX = MY = TRS = BRS = 0)

• Display blank (E = D = 0)

• Address counter X[6:0] = 0 and Y[3:0] = 0

• Temperature coefficient (TC[1:0] = 0)

• Bias system (BS[2:0] = 0)

• After power-on (RAM data is undefined), the reset signal does not change the content of the RAM.

BIT

0

1

RESET STATE

PD

chip is active

chip is in Power-down mode

1

V

horizontal addressing

vertical addressing

0

H

use basic instruction set

use extended instruction set

0

MX

normal X addressing

X address is mirrored

0

MY

display is not vertically mirrored

display is vertically mirrored

0

TRS

top rows are not mirrored

top rows are mirrored

0

BRS

bottom rows are not mirrored

bottom rows are mirrored

0

DO

MSB is on top

LSB is on top

0

PRS

0

D and E

00

display blank

D = 0

E=0

10

normal mode

01

all display segments on

11

inverse video mode

TC[1:0]

00

TC[1:0] = 00

01

10

11

S[1:0]

00

2

× voltage multiplier

S[1:0] = 00

01

3

× voltage multiplier

10

4

× voltage multiplier

11

5

× voltage multiplier

BS[2:0]

bias system

BS[2:0] = 000