PCF2119AUSLASH2DASLASH2 datasheet(38/79 Pages) NXP

38 / 79 page

PCF2119X_5

Product data sheet

Rev. 05 — 13 August 2009

38 of 79

NXP Semiconductors

PCF2119x

LCD controllers/drivers

10.2.3.6

VLCD_set

The VLCD value is calculated with the Equation 2 on page 8. The multiplication factor is

programmed by instruction. Two on-chip registers (VA and VB) hold the multiplication

factor for the character mode and the icon mode, respectively. The generated VLCDOUT

value is independent of VDD, allowing battery operation of the chip.

Vx programming:

1. Send Function_set instruction with bit H = 1.

2. Send VLCD_set instruction to write to the voltage register:

a. Bit 7 = 1 and bit 6 = 0: bit 5 to bit 0 are the multiplication factor for VLCD of character

mode (VA).

b. Bit 7 = 1 and bit 6 = 1: bit 5 to bit 0 are the multiplication factor for VLCD of icon

mode (VB).

c. Bit 5 to bit 0 = 0 switches VLCD generator off (when selected).

d. During ‘display off’/power-down the VLCD generator is also disabled.

3. Send Function_set instruction with bit H = 0 to resume normal programming.

Table 32.

VLCD_set bit description

Bit

Symbol

Value

Description

see Table 10

R/W-

ﬁxed value

set register VA or VB

set register VA

set register VB

5 to 0

VA or VB

000000 to

111111

factor for calculating VLCD

PCF2119AU/2DA/2 Datasheet(PDF) 38 Page - NXP Semiconductors