Epson S1C63558 (2)Switching of drive duty

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (LCD Driver)

(2)Switching of drive duty

In the S1C63558, the drive duty can be set to 1/17, 1/16 or 1/8 by the software. This setting is done using the LDUTY1 and LDUTY0 registers as shown in Table 4.7.4.1.

Table 4.7.4.1 LCD drive duty setting

LDUTY1	LDUTY0	Drive	Common terminal	Maximum segment		When 48 ⋅ 8 mask option
		duty	used	number		is selected
1	∗	1/8	COM0–COM7	320 (40 ⋅	8)	384 (48 ⋅ 8)
0	1	1/16	COM0–COM15	640 (40 ⋅	16)	Invalid
0	0	1/17	COM0–COM16	680 (40 ⋅	17)	Invalid

When 48 segments ⋅ 8 commons is selected by mask option, COM8–COM16 are changed to SEG47– SEG40. Therefore, COM8–COM16 cannot be used. In this case, be sure to set the drive duty to 1/8 by the software.

Table 4.7.4.2 shows the frame frequencies corresponding to the OSC1 oscillation frequency and drive duty.

	Table 4.7.4.2	Frame frequency
OSC1 oscillation	When 1/8 duty	When 1/16 duty	When 1/17 duty
frequency	is selected	is selected	is selected
32.768 kHz	32 Hz	32 Hz	30.12 Hz

Figure 4.7.4.1 shows the dynamic drive waveform for 1/4 bias.

Drive duty 1/8	0	1	2	3	. . . . . 7		0	1	2	3	. . . . . 7		(LPAGE = 0)
1/16	0	1	2	3	. . . . .	15	0	1	2	3	. . . . .	15
1/17	0	1	2	3	. . . . .	16	0	1	2	3	. . . . .	16
Frame signal														∗ When fOSC1 = 32.768 kHz
						32	Hz ∗
														VC5
														VC4
														VC23 (VC2 = VC3)
COM0
														VC1
														VSS
														VC5
														VC4
														VC23 (VC2 = VC3)
COM1
														VC1
														VSS
														VC5
														VC4
														VC23 (VC2 = VC3)
COM2
														VC1
														VSS

VC5

VC4

SEG0 VC23 (VC2 = VC3) VC1

VSS

VC5

VC4

SEG1 VC23 (VC2 = VC3) VC1

VSS

Fig. 4.7.4.1 Drive waveform for 1/4 bias

50 EPSON S1C63558 TECHNICAL MANUAL