Lcd Control Register 2 (Lcr2) - Hitachi HD6473867 Hardware Manual

13.2.3

LCD Control Register 2 (LCR2)

Bit
LCDAB
Initial value
Read/Write R/W
LCR2 is an 8-bit read/write register which controls switching between the A waveform and B
waveform, selects the drive power supply, controls the step-up constant-voltage (5 V) power
supply, and selects the duty cycle of the charge/discharge pulses which control disconnection of
the power supply split-resistance from the power supply circuit.
LCR2 is initialized to H'60 upon reset.
Bit 7: A waveform/B waveform switching control (LCDAB)
Bit 7 specifies whether the A waveform or B waveform is used as the LCD drive waveform.
Bit 7
LCDAB Description
0 Drive using A waveform
1 Drive using B waveform
Bits 6 and 5: Reserved bits
Bits 6 and 5 are reserved; they are always read as 1 and cannot be modified.
Bit 4: Drive power supply select, step-up constant-voltage (5 V) power supply control (SUPS)
(Applies to the H8/3867 Series only)
When V is selected as the drive power supply, the step-up constant-voltage (5 V) power supply
CC
simultaneously stops operating; when 5 V is selected as the drive power supply, the step-up
constant-voltage (5 V) power supply simultaneously operates.
Bit 4
SUPS Description
0 Drive power supply is V
1 Drive power supply is 5 V, step-up constant-voltage (5 V) power supply operates
7 6
— —
0 1
— —
, step-up constant-voltage (5 V) power supply halts
CC
5 4 3
SUPS CDS3
1 0 0
R/W R/W
333
2 1
CDS2 CDS1 CDS0
0 0
R/W R/W
(initial value)
(Initial value)
0
0
R/W