Register Descriptions; Lcd Port Control Register (Lpcr) - Hitachi H8S/2646 Hardware Manual

18.2

Register Descriptions

18.2.1

LCD Port Control Register (LPCR)

Bit 7
DTS1
Initial value 0
Read/Write R/W
LPCR is an 8-bit read/write register which selects the duty cycle, LCD driver, and pin functions.
LPCR is initialized to H'00 upon reset and in standby mode.
Bits 7 to 5—Duty Cycle Select 1 and 0 (DTS1, DTS0), Common Function Select (CMX): The
combination of DTS1 and DTS0 selects static, 1/2, 1/3, or 1/4 duty. CMX specifies whether or not
the same waveform is to be output from multiple pins to increase the common drive power when
not all common pins are used because of the duty setting.
Bit 7: Bit 6: Bit 5:
DTS1 DTS0 CMX
0 0 0
1
1 0
1
1 0 0
1
1
*
Note: COM4 to COM1 function as ports when the setting of SGS3 to SGS0 is 0000 (initial value).
Bit 4—Reserved: This bit is always read as 0 and should only be written with 0.
634
6 5
DTS0 CMX
0 0
R/W R/W
Duty Cycle Common Drivers
Static COM1
COM4 to COM1
1/2 duty COM2 to COM1
COM4 to COM1
1/3 duty COM3 to COM1
COM4 to COM1
1/4 duty COM4 to COM1
4 3
— SGS3 SGS2
0 0
— R/W R/W
Notes
COM4, COM3, and COM2 can
be used as ports
COM4, COM3, and COM2 output
the same waveform as COM1
COM4 and COM3 can be used
as ports
COM4 outputs the same
waveform as COM3, and COM2
outputs the same waveform as
COM1
COM4 can be used as a port
Do not use COM4
—
2 1 0
SGS1 SGS0
0 0 0
R/W R/W
(Initial value)
*: Don't care