Epson Research and Development
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Vancouver Design Center
Programming Notes and Examples
SED1352
Issue Date: 98/10/08
X16-BG-007-04
3.2.3 Four Gray Shades (Two Bits/Pixel)
When the SED1352 is configured for two bit pixels, each pixel can index one of four LUT entries. In this 4 gray shade
mode, the SED1352 treats the 16 entries in the LUT as four separate look-up tables or banks, each having four entries (see
Figure 3). The following examples show how to program and select these banks.
Example 5:
In 4 gray shade mode, program bank 2 LUT entries and select for use.
1.
Determine location of bank 2 in LUT.
The first four entries in the 16 entry LUT represent the first bank (bank 0). The following four entries in the LUT rep-
resent the second bank (bank 1), etc. Consequently bank 2 starts at LUT index 8 as shown below:
Bank 2 is shown in Figure 3, palette 2.
2.
Write LUT index to Look-Up Table Address Register AUX[0Eh].
For bank 2, the index will one of the following values: 08h, 09h, 0Ah, or 0Bh
3.
Write LUT entry value to Look-Up Table Data Register AUX[0Fh].
For a linear LUT, use the look-up table entries in Table 3-1, “SED1352F0B Black-To-White Look-Up Table for 16
Gray Shades,” on page 17.
4.
Repeat steps 2 and 3 until all 4 LUT entries have been written.
5.
To display data using Bank 2 write 10b to AUX[0E] bits 7,6.
Table 3-3: SED1352F0B Black-To-White Look-Up Table for 4 Gray Shades
Index
(hex)
Look-Up
Table
(hex)
0
0
1
5
2
A
3
F
start of bank index
bank number
4
×
=
start of bank 2
2
4
×
8
=
=
