Epson S1D13504 manual Look-Up Table LUT, REG24h Look-Up Table Address Register Read/Write

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3.3 Look-Up Table (LUT)

This section provides a description of the LUT registers, followed by a description of the color and gray shade LUTs and a discussion of the banks available in the 2 and 8 bit-per-pixel (bpp) modes.

The S1D13504 LUT is only used for the panel interface. The optional RAMDAC is used to determine the colors for the CRT. See Section 6, “CRT Considerations” on page 33.

3.3.1 Look-Up Table Registers

REG[24h] Look-Up Table Address Register							Read/Write
n/a	n/a	RGB Index	RGB Index	LUT Address	LUT Address	LUT Address		LUT Address
		Bit 1	Bit 0	Bit 3	Bit 2	Bit 1		Bit 0

REG[26h] Look-Up Table Data Register						Read/Write
n/a	n/a	n/a	n/a	LUT Data	LUT Data	LUT Data		LUT Data
				Bit 3	Bit 2	Bit 1		Bit 0
REG[27h] Look-Up Table Bank Register							Read/Write
n/a	n/a	Red Bank	Red Bank	Blue Bank	Blue Bank	Green Bank		Green Bank
		Select Bit 1	Select Bit 0	Select Bit 1	Select Bit 0	Select Bit 1		Select Bit 0

The S1D13504 LUT Registers are located at offsets 24h, 26h and 27h. They consist of a LUT address register, data register and bank register. Refer to the S1D13504 Hardware Functional Speci- fication document number X19A-A-002-xx for more details.

RGB Index

Selects which LUT to program. If set for Auto-increment, it will start at the Red LUT of the Index selected. Then with consecutive writes/reads it will increment to Green, then Blue of the same index, it will then increment the index and start at the Red LUT again.

Auto-increment algorithm:

1.Set RGB Index to 0 for Auto-increment, set LUT address to 0 (i.e. REG[24h]=00h).

2.While count < or = to (16*3), write data byte to REG[26h].

R, G or B Index select algorithm:

1.Set RGB Index to R(01b), G(10b), or B(11b), set LUT address to 0 (e.g. REG[24h]=10h).

2.While count < or = 16, write data byte to REG[26h], increment LUT address.

LUT Address

Selects start index of the LUT in which to read data from, or write data to. Bank select has no effect on the CPU read/write to the LUT.

LUT Data

4-bit data value to write.

Programming Notes and Examples	S1D13504
Issue Date: 01/02/01	X19A-G-002-07