1997 Jul 03

17

Philips Semiconductors

Product specification

8-bit microcontrollers with LCD-driver

P83C434; P83C834

6.6.5

After an external or Power-on-reset the LCD Control Register holds the value 0CH (see Table 10) resulting in:

• Bits MD0 and MD1 reset the multiplex ratio to the 1 : 4 mode.

Table 17 LCD Control Register (address B9H)

Table 18 Description of LCDCON bits

Table 19 Multiplex ratio mode selection

6.6.6

The 12 display registers, LCD0 to LCD11, are 8-bit derivative (Read/Write) registers which store LCD segment data.

For detailed information, regarding the LCD0 to LCD11, see Table 23 in Section 6.7.7.

76543210

−−−−

MD1

MD0

BIAS

ENLCD

BIT

SYMBOL

DESCRIPTION

7to4

−

Reserved.

3

MD1

Mode bits. MD0 and MD1 determine the multiplex rate; see Table 19.

2

MD0

1

BIAS

The BIAS bit sets the LCD voltage bias generator. If BIAS is:

0

ENLCD

Enable LCD. If ENLCD is:

LOW, then the LCD is disabled.

HIGH, then the LCD is enabled and character display is possible.

MD1

MD0

MULTIPLEX RATIO MODE

0

0

static

0

1

1:2

1

0

1:3

1

1

1:4