HD66773R Datasheet, PDF (88/133 Pages) Renesas Technology Corp – 262,144-color, 132 x 176-dot Graphics Controller Driver for TFT LCD panels

HD66773R
γ-Correction Registers
Register
Groups
Gradient
adjustment
Amplitude
adjustment
Fine adjustment
Positive
Polarity
PRP0 2 to 0
PRP1 2 to 0
VRP0 3 to 0
VRP1 4 to 0
PKP0 2 to 0
PKP1 2 to 0
PKP2 2 to 0
PKP3 2 to 0
PKP4 2 to 0
PKP5 2 to 0
Negative
Polarity
PRN0 2 to 0
PRN1 2 to 0
VRN0 3 to 0
VRN1 4 to 0
PKN0 2 to 0
PKN1 2 to 0
PKN2 2 to 0
PKN3 2 to 0
PKN4 2 to 0
PKN5 2 to 0
Description
Variable resistor VRHP (N)
Variable resistor VRLP (N)
Variable resistor VRP (N)0
Variable resistor VRP (N)1
8-to-1 selector (voltage level of grayscale 1)
8-to-1 selector (voltage level of grayscale 8)
8-to-1 selector (voltage level of grayscale 20)
8-to-1 selector (voltage level of grayscale 43)
8-to-1 selector (voltage level of grayscale 55)
8-to-1 selector (voltage level of grayscale 62)
Ladder resistors and 8-to-1 selector
Block configuration
The block diagram of page 86 consists of two ladder resistors including variable resistors, and 8-to-1
selectors which select the voltage generated by the ladder resistors to output a reference voltage for the
grayscale voltage. The variable resistors and the 8-to-1 selectors are controlled by the γ correction register.
Pins to be connected to a variable resistor are provided to compensate the variation among the panels.
Variable resistor
There are two kinds of variable resistors for the gradient adjustment (VRHP(N)/VRLP(N)) and the
amplitude adjustment (VRP(N)0/ VRP(N)1). The resistance is determined by the gradient adjustment and
amplitude adjustment registers as is shown below.
Gradient adjustment (1)
Register value Resistance
PRP(N)0[2:0] VRHP(N)
000
0R
001
4R
010
8R
011
12R
100
16R
101
20R
110
24R
111
28R
Gradient adjustment (2)
Register value Resistance
PRP(N)1[2:0] VRLP(N)
000
0R
001
4R
010
8R
011
12R
100
16R
101
20R
110
24R
111
28R
Rev.1.10, Jun.21.2003, page 88 of 133