PCF2119X Datasheet, PDF (38/79 Pages) NXP Semiconductors – LCD controllers/drivers

NXP Semiconductors
PCF2119x
LCD controllers/drivers
10.2.3.6 VLCD_set
Table 32. VLCD_set bit description
Bit
Symbol
Value
RS
-
0
R/W -
0
7
-
1
6
V
0
1
5 to 0 V_A or V_B
000000 to
11 1111
Description
see Table 10
fixed value
set register V_A or V_B
set register V_A
set register V_B
factor for calculating V_LCD
The V_LCD value is calculated with the Equation 2 on page 8. The multiplication factor is
programmed by instruction. Two on-chip registers (V_A and V_B) hold the multiplication
factor for the character mode and the icon mode, respectively. The generated V_LCDOUT
value is independent of V_DD, allowing battery operation of the chip.
V_x 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 V_LCD of character
mode (V_A).
b. Bit 7 = 1 and bit 6 = 1: bit 5 to bit 0 are the multiplication factor for V_LCD of icon
mode (V_B).
c. Bit 5 to bit 0 = 0 switches V_LCD generator off (when selected).
d. During ‘display off’/power-down the V_LCD generator is also disabled.
3. Send Function_set instruction with bit H = 0 to resume normal programming.
PCF2119X_5
Product data sheet
Rev. 05 — 13 August 2009
© NXP B.V. 2009. All rights reserved.
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