Page 54
Epson Research and Development
Vancouver Design Center
SED1352
Hardware Functional Specification
X16-SP-001-16
Issue Date: 99/07/28
bits 3-0
Palette Data Bits [3:0]
These 4-bits are the gray shade values used for display data output. They are programmed into the 4-bit
Look-Up Table (palettes) positions pointed to by Palette Address bits [3:0].
For example: in a 16-level gray shade display mode, a data value of 0001b (4-bits / pixel) will point to
Look-Up Table position one and display the 4-bit gray shade corresponding to the value programmed into
that location.
8.2 Look-Up Table Architecture
8.2.1 4-Level Gray Shade Mode
Figure 27: 4-Level Gray-Shade Mode Look-Up Table Architecture
AUX[0Fh] Look-Up Table Data Register
I/O address = 1111b, Read/Write.
n/a
n/a
n/a
n/a
Palette Data
Bit 3
Palette Data
Bit 2
Palette Data
Bit 1
Palette Data
Bit 0
Look-Up Table
0
1
2
3
2 bit pixel data
0
1
2
3
0
1
2
3
0
1
2
3
Bank 0
Bank 1
Bank 2
Bank 3
Bank Select bits [1:0]
(Aux[0Eh] bits [7:6])
4-bit display data output
Bank
Select
Logic
Note: the above depiction is intended to show the display data output path only. The CPU R/W access to the individual
Look-Up Tables is not affected by the various ‘banking’ configurations.