E202075_HD404889 Datasheet, PDF (144/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
LCD duty/clock control register (LMR: $02D):
The LCD duty/clock control register is a 4-bit write-only register used to set four kinds of display duty ratio
and LCD reference clock (figure 89). Table 27 shows the LCD frame frequencies for each duty setting.
LCD duty/clock control register (LMR: $02D)
Bit
Read/Write
Initial value on reset
Bit name
3
W
0
LMR3
2
W
0
LMR2
1
W
0
LMR1
0
W
0
LMR0
LMR1 LMR0
0
0
1
0
1
1
Duty factor
1/4
1/3
1/2
1 (static drive)
LMR3
0
1
LMR2
0
1
0
1
LCD circuit clock
CL0=32.768kHz × Duty/128
CL1=32.768kHz × Duty/256
CL2=øPER × Duty/256
When TMA3 = 0, CL3 =øPER × Duty/2048
When TMA3 = 1, CL3 = 32.768 kHz × Duty/512
Figure 89 LCD Duty/Clock Control Register (LMR)
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