HD66781 Datasheet, PDF (172/196 Pages) Renesas Technology Corp – 720-channel Source Driver for a-Si TFT/Low Temperature Poly-Si TFT Panels with 262,144-color display RAM

HD66781
Preliminary
8-color Display Mode
The HD66781 incorporates an 8-color display mode. The available grayscale levels are V0 and V63, and
the voltages for the other levels (V1-V62) are halted to reduce power consumption.
The γ-fine-adjustment registers, PKP0-PKP5 and PKN0-PKN5 are not available in the 8-color display
mode. Since the power supplies for the levels V1-V62 are halted in the 8-color mode, data are converted to
automatically select V0/V63 levels: the MSB of each R, G, B, pixel of GRAM data is allocated to the lower
5 bits of R, G, B of display data. The HD 66781 enables to switch between 8-color and normal display
modes without rewriting GRAM data only with the COL setting.
+ polar register
PKP0[2:0]
PKP1[2:0]
PKP2[2:0]
PKP3[2:0]
PKP4[2:0]
PKP5[2:0]
PRP0[2:0]
PRP1[2:0]
VRP0[3:0]
VRP1[4:0]
COL[1:0]=h'2
GRAM
MSB
LSB
R5 R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B5 B4 B3 B2 B1 B0
- polar register
PKN0[2:0]
PKN1[2:0]
PKN2[2:0]
PKN3[2:0]
P KN4[2:0]
P KN5[2:0]
P RN0[2:0]
P RN1[2:0]
V RN0[3:0]
V RN1[4:0]
Display data R5 R5 R5 R5 R5 R5 G5 G5 G5 G5 G5 G5 B5 B5 B5 B5 B5 B5
V0
6
6
6
8
2
2 gray- scale
control
<R>
2 gray- scale
control
<G>
2 gray- scale
control
<B>
V63
LCD driver
LCD driver
LCD driver
RGB
L^LC^CD ^D
Rev.0.5, July.31.2003, page 172 of 196