26 LCD CONTROLLER (LCDC)
26-38
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
The LCD controller is placed in power-save mode by setting PSAVE[1:0] to 0x0. In this mode, all LCD
signal output pins are dropped low and all operations of the LCD controller, other than accessing of its
control registers and look-up tables are disabled. The LCD controller is taken out of power-save mode
by setting PSAVE[1:0] to 0x3.
Horizontal Display Register (LCDC_HDISP)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
Horizontal
Display
Register
(LCDC_HDISP)
0x302010
(32 bits)
D31–23 –
reserved
–
–
–
0 when being read.
D22–16 HTCNT[6:0] Horizontal total period (HT) setup
HT = HDP + HNDP
HT > HDPS + HDP (for HR-TFT)
HT = (HTCNT + 1)
×
8 [Ts]
HNDP = (HTCNT - HDPCNT)
×
8 [Ts]
0x0 R/W
D15–7 –
reserved
–
–
–
0 when being read.
D6–0 HDPCNT
[6:0]
Horizontal display period (HDP)
setup
HDP = ( 1)
×
8 [Ts] 0x0 R/W
D[31:23] Reserved
D[22:16] HTCNT[6:0]: Horizontal Total Period (HT) Setup Bits
Sets the horizontal total period (HT) in 8-pixel increments. (Default: 0x0)
HT = (HTCNT[6:0] + 1)
×
8 [Ts]
(Ts: pixel clock period)
The horizontal total period contains horizontal display period and horizontal non-display period and the
maximum value that can be set is 1,024-pixel period.
The following conditions must be satisfied when setting HTCNT[6:0]:
HTCNT[6:0]
≥
HDPCNT[6:0] + 3
HT > HDP + HDPS
Note: HT should be determined so that the horizontal non-display period (HNDP = HT - HDP) will be
longer than the time required when the LCDC accesses eight words in the VRAM.
D[15:7] Reserved
D[6:0]
HDPCNT[6:0]: Horizontal Display Period (HDP) Setup Bits
Sets the horizontal display period (HDP, panel horizontal resolution) in 8-pixel increments. (Default:
0x0)
HDP = (HDPCNT[6:0] + 1)
×
8 [Ts]
The following condition must be satisfied when setting HDPCNT[6:0]:
HDP
≥
16 (HDPCNT[6:0]
≥
1)
Example: when 320
×
240 LCD (STN/TFT) panel is used
HDP = 320
HDPCNT[6:0] = 320/8 - 1 = 39 (= 0x27)
Vertical Display Register (LCDC_VDISP)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
Vertical Display
Register
(LCDC_VDISP)
0x302014
(32 bits)
D31–26 –
reserved
–
–
–
0 when being read.
D25–16 VTCNT[9:0] Vertical total period (VT) setup
VT = VDP + VNDP
VT > VDPS + VDP (for HR-TFT)
VT = VTCNT + 1 [lines]
VNDP = VTCNT - VDPCNT
[lines]
0x0 R/W
D15–10 –
reserved
–
–
–
0 when being read.
D9–0 VDPCNT
[9:0]
Vertical display period (VDP)
setup
VDP = 1 [lines]
0x0 R/W
D[31:26] Reserved
D[25:16] VTCNT[9:0]: Vertical Total Period (VT) Setup Bits
Sets the vertical total period (VT) in line units. (Default: 0x0)
VT = VTCNT[9:0] + 1 [lines]
The vertical total period contains vertical display period and vertical non-display period and the maxi-
mum value that can be set is 1,024 lines.