Hitachi H8S/2645, Hardware Manual

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18.2.2 LCD Control Register (LCR)
Bit 7 6 5 4 3 2 1 0
— PSW ACT DISP CKS3 CKS2 CKS1 CKS0
Initial value 1 0 0 0 0 0 0 0
Read/Write — R/W R/W R/W R/W R/W R/W R/W
LCR is an 8-bit read/write register which performs LCD power supply split-resistance connection
control and display data control, and selects the frame frequency.
LCR is initialized to H'80 upon reset and in standby mode.
Bit 7—Reserved: This bit is always read as 1 and cannot be modified.
Bit 6—LCD Power Supply Split-Resistance Connection Control (PSW): Bit 6 can be used to
disconnect the LCD power supply split-resistance 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 standby mode, the LCD power supply split-resistance is disconnected from V
CC
regardless of the setting of this bit.
Bit 6: PSW Description
0 LCD power supply split-resistance is disconnected from V
CC
(Initial value)
1 LCD power supply split-resistance is connected to V
CC
Bit 5—Display Function Activate (ACT): Bit 5 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 ladder resistance is also turned off, regardless of the setting of the PSW
bit. However, register contents are retained.
Bit 5: ACT Description
0 LCD controller/driver operation halted (Initial value)
1 LCD controller/driver operates
Bit 4—Display Data Control (DISP): Bit 4 specifies whether the LCD RAM contents are
displayed or blank data is displayed regardless of the LCD RAM contents.
Bit 4: DISP Description
0 Blank data is displayed (Initial value)
1 LCD RAM data is display