23 lCD DRiVeR (lCD)
S1C17624/604/622/602/621 TeChniCal Manual
Seiko epson Corporation
23-3
When the clock source is OSC1
3.2.1 Frame Frequency Settings (when OSC1 = 32.768 kHz)
Table 23.
Drive duty
(lDuTY[2:0] setting)
FRMCnT[1:0] setting (lClK division ratio)
0x0
0x1
0x2
0x3
1/8 duty (0x4)
128 Hz (1/256)
64 Hz (1/512)
*
48.19 Hz (1/680)
32 Hz (1/1024)
1/4 duty (0x3)
128 Hz (1/256)
64 Hz (1/512)
48.19 Hz (1/680)
32 Hz (1/1024)
1/3 duty (0x2)
130.04 Hz (1/252)
65.02 Hz (1/504)
48.12 Hz (1/681)
32.5 Hz (1/1008)
1/2 duty (0x1)
128 Hz (1/256)
64 Hz (1/512)
48.19 Hz (1/680)
32 Hz (1/1024)
Static (0x0)
128 Hz (1/256)
64 Hz (1/512)
48.19 Hz (1/680)
32 Hz (1/1024)
*
Default setting
When the clock source is hSClK
3.2.2 Frame Frequency Settings
Table 23.
Drive duty
(lDuTY[2:0] setting)
FRMCnT[1:0] setting
0x0
0x1
0x2
0x3
1/8 duty (0x4)
f
HSCLK
×
LCKDV
––––––––––––––
256
f
HSCLK
×
LCKDV
*
––––––––––––––
512
f
HSCLK
×
LCKDV
––––––––––––––
680
f
HSCLK
×
LCKDV
––––––––––––––
1024
1/4 duty (0x3)
f
HSCLK
×
LCKDV
––––––––––––––
256
f
HSCLK
×
LCKDV
––––––––––––––
512
f
HSCLK
×
LCKDV
––––––––––––––
680
f
HSCLK
×
LCKDV
––––––––––––––
1024
1/3 duty (0x2)
f
HSCLK
×
LCKDV
––––––––––––––
252
f
HSCLK
×
LCKDV
––––––––––––––
504
f
HSCLK
×
LCKDV
––––––––––––––
681
f
HSCLK
×
LCKDV
––––––––––––––
1008
1/2 duty (0x1)
f
HSCLK
×
LCKDV
––––––––––––––
256
f
HSCLK
×
LCKDV
––––––––––––––
512
f
HSCLK
×
LCKDV
––––––––––––––
680
f
HSCLK
×
LCKDV
––––––––––––––
1024
Static (0x0)
f
HSCLK
×
LCKDV
––––––––––––––
256
f
HSCLK
×
LCKDV
––––––––––––––
512
f
HSCLK
×
LCKDV
––––––––––––––
680
f
HSCLK
×
LCKDV
––––––––––––––
1024
*
Default setting, f
HSCLK
: HSCLK (IOSC or OSC3) clock frequency, LCKDV: HSCLK division ratio (1/32 to 1/512)
The frame signal generated can be output to an external device via the LFRO pin. To output the frame signal, set
LFROUT/LCD_CCTL register to 1. However, the output pin must be switched for LFRO output using the port
function select bit, as the pin is configured for an I/O port by default. For detailed information on pin function
switching, see the “I/O Ports (P)” chapter.
Drive Duty Control
23.4
Drive Duty Switching
23.4.1
Drive duty can be set to 1/8, 1/4, 1/3, 1/2 or static drive using LDUTY[2:0]/LCD_CCTL register. Tables 23.4.1.1
and 23.4.1.2 show the correspondence between LDUTY[2:0] settings, drive duty, and maximum number of display
segments.
S1C17624/622
4.1.1 Drive Duty Settings (S1C17624/622)
Table 23.
lDuTY[2:0]
Duty
Valid COM pins
Valid SeG pins
Max. number of
display segments
0x7–0x5
Reserved
–
–
–
0x4
1/8
COM0 to COM7
SEG0 to SEG51
416 segments
0x3
1/4
COM0 to COM3
SEG0 to SEG55
224 segments
0x2
1/3
COM0 to COM2
SEG0 to SEG55
168 segments
0x1
1/2
COM0 to COM1
SEG0 to SEG55
112 segments
0x0
Static
COM0
SEG0 to SEG55
56 segments
(Default: 0x4)
The COM4/SEG55 to COM7/SEG52 pins are configured to COM pins when 1/8 duty is selected or SEG pins
when other duty is selected.