HX8347 - Adafruit

HX8347-G(T)240RGB x 320 dot, 262K color, TFT Mobile Single Chip DriverGamma-characteristics adjustment registersDATA SHEET Preliminary V01This HX8347-G has register groups for specifying a series grayscale voltage thatmeets the Gamma-characteristics for the LCD panel used. These registers aredivided into two groups, which correspond to the gradient, amplitude, and macroadjustment of the voltage for the grayscale characteristics. The polarity of eachregister can be specified independently.Offset adjustment registersThe offset adjustment variable registers are used to adjust the amplitude of thegrayscale voltage. This function is implemented by controlling these variable resistersin the top and bottom of the gamma resister stream for reference gamma voltagegeneration. These registers are available for both positive and negative polaritiesGamma center adjustment registersThe gamma center adjustment registers are used to adjust the reference gammavoltage in the middle level of grayscale without changing the dynamic range. Thisfunction is implemented by choosing one input of 128-to-1 selector in the gammaresister stream for reference gamma voltage generation. These registers areavailable for both positive and negative polarities.Gamma macro adjustment registersThe gamma macro adjustment registers can be used for fine adjustment of thereference gamma voltage. This function is implemented by controlling the 32-to-1selectors (PKP/N0~5), each of which has 5 inputs and generates one referencevoltage output (Vg(P/N) 3, 20, 32(31), 43, 60).Register Positive NegativeGroups Polarity PolarityDescriptionCenter PRP0 6-0 PRN0 6-0 Variable resistor (PRP/N0) for center adjustmentAdjustment PRP1 6-0 PRN1 6-0 Variable resistor (PRP/N1)for center adjustmentPKP0 4-0 PKN0 4-0 32-to-1 selector (voltage level of grayscale 3)PKP1 4-0 PKN1 4-0 32-to-1 selector (voltage level of grayscale 20)Macro32-to-1 selector (voltage level of grayscale 32 for positive polarityPKP2 4-0 PKN2 4-0Adjustmentand grayscale 31 for negative polarity)OffsetAdjustmentPKP3 4-0 PKN3 4-0 32-to-1 selector (voltage level of grayscale 43)PKP4 4-0 PKN4 4-0 32-to-1 selector (voltage level of grayscale 60)VRP0 5-0 VRN0 5-0 Variable resistor (VRP/N0)for offset adjustmentVRP1 5-0 VRN1 5-0 Variable resistor (VRP/N1)for offset adjustmentVRP2 5-0 VRN2 5-0 Variable resistor (VRP/N2)for offset adjustmentVRP3 5-0 VRN3 5-0 Variable resistor (VRP/N3)for offset adjustmentVRP4 5-0 VRN4 5-0 Variable resistor (VRP/N4)for offset adjustmentVRP5 5-0 VRN5 5-0 Variable resistor (VRP/N5)for offset adjustmentTable 5.12: Gamma-adjustment registersHimax ConfidentialFor Go-tek OnlyThis information contained herein is the exclusive property of Himax and shall not be distributed, reproduced, or disclosedin whole or in part without prior written permission of Himax.-P.85-October, 2009