H8S Family
LCD Display Using 1/4 Duty Drive (LCD Controller/Driver)
REJ06B0486-0100/Rev.1.00
March 2005
Page 13 of 19
Table 4 Internal Registers Used (cont)
Register
Bit Name
Description
Address
Set Value
LCR
LCD control register
H'FFFFC1
H'31
PSW
LCD power supply split-resistor connection control
This bit can be used to disconnect the LCD power
supply split-resistors from V
CC
when LCD display is not
required in a power-down mode or when an external
power supply is used. When the ACT bit is cleared to
0, and also in the standby mode, the LCD power
supply split-resistors are disconnected from V
CC
regardless of the setting of this bit.
•
PSW = 0: LCD power supply split-resistors are
disconnected from V
CC
•
PSW = 1: LCD power supply split-resistors are
connected to V
CC
Bit 6
0
ACT
Display
function
activate
This bit specifies whether or not the LCD
controller/driver is used. Clearing this bit to 0 halts
operation of the LCD controller/driver. The LCD drive
power supply is also turned off, regardless of the
setting of the PSW bit. However, register contents are
retained.
•
ACT = 0: LCD controller/driver operation disabled
•
ACT = 1: LCD controller/driver operation enabled
Bit 5
1
DISP
Display
data
control
This bit specifies whether the contents of LCD RAM
are displayed or blank data is displayed regardless of
the LCD RAM contents.
•
DISP = 0: Blank data is displayed
•
DISP = 1: LCD RAM data is displayed
Bit 4
1
CKS3
CKS2
CKS1
CKS0
Frame frequency select 3 to 0
These bits select the clock source and frame
frequency.
•
CKS3 = 0, CKS2 = 0, CKS1 = 0, CKS0 = 1:
φ
SUB/2 selected as the clock source and 64 Hz
selected as the frame frequency
Bit 3
Bit 2
Bit 1
Bit 0
CKS3 = 0
CKS2 = 0
CKS1 = 1
CKS0 = 1
