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Vancouver Design Center
Hardware Functional Specification S1D13504
Issue Date: 01/01/30 X19A-A-002-18
bits 3-0 LUT Address Bits [3:0]
These 4 bits provide a pointer into the 16 position Look-Up Table currently selected for CPU
read/write access.
The Look-Up Table configuration (e.g. 1/2/4 banks) does not affect the read/write access from the
CPU as all 16 positions can be accessed sequentially.
bits 3-0 LUT Data Bits [3:0]
These 4 bits are the gray shade/color values used for display data output. They are programmed into
the 4-bit Look-Up Table positions pointed to by LUT Address bits [3:0] and RGB Index bits [1:0]
(if in color display modes).
For example: in a 16-level gray shade display mode, a data value of 0001b (4 bits-per-pixel) will
point to Look-Up Table position one and display the 4-bit gray shade corresponding to the value
programmed into that location.
bit 5-4 Red Bank Select Bits [ 1:0]
In 2-bpp mode, the 16 position Red LUT is arranged into four, 4 position “banks.” Th ese two bits
control which bank is currently selected.
In 8-bpp mode, the 16 position Red LUT is arranged into two, 8 position “banks.” Only bit 0 of
these two bits controls which bank is currently selected.
These bits have no effect in 1-bpp, 4-bpp, 15/16-bpp mode, or all monochrome modes.
bit 3-2 Blue Bank Select Bits [1:0]
In both 2-bpp and 8-bpp modes, the 16 position Blue LUT is arranged into four 4 position “banks.”
These two bits control which bank is currently selected.
These bits have no effect in 1-bpp, 4-bpp, 15/16-bpp mode, or all monochrome modes.
bits 1-0 Green Bank Select Bits [1:0]
In 2-bpp mode, the 16 position Green LUT is arranged into four, 4 p osition “banks .” Thes e tw o bit s
control which bank is currently selected.
In 8-bpp mode, the 16 position Green LUT is arranged into two, 8 position “banks.” Only bit 0 of
these two bits controls which bank is currently selected.
These bits have no effect in 1-bpp, 4-bpp, and 15/16-bpp modes.
Look-Up Table Data Register
REG[26h] RW
n/a n/a n/a n/a LUT Data
Bit 3 LUT Data
Bit 2 LUT Data
Bit 1 LUT Da ta
Bit 0
Look-Up Table Bank Select Register
REG[27h] RW
n/a n/a Red Bank
Select Bit 1 Red Bank
Select Bit 0 Blue Bank
Select Bit 1 Blue Bank
Select Bit 0 Green Bank
Select Bit 1 Green Bank
Select Bit 0