Page 26 Epson Research and Development
Vancouver Design Center
S1D13504 Programming Notes and Examples
X19A-G-002-07 Issue Date: 01/02/01
4.2.1 Registers

These three registers form the address of the word in the display buffer where screen 1 will start

displaying from. Changing these registers by one will cause a change of 0 to 16 pixels depending on

the current color depth. Refer to the following table to see the minimum number of pixels affected

by a change of one to these registers.

The pixel panning register offers finer control over pixel pans than is available with th e Start Address

Registers. Using this register it is possible to pan the displayed image one pixel at a time. Depending

on the current color depth certain bits of the pixel pan register are not used. The following table

shows this.

REG[10h] Screen 1 Display Start Address 0
Start Address
Bit 7 Start Address
Bit 6 Start Address
Bit 5 Start Address
Bit 4 Start Address
Bit 3 Start Address
Bit 2 Start Address
Bit 1 Start Address
Bit 0
REG[11h] Screen 1 Display Start Address 1
Start Address
Bit 15 Start Address
Bit 14 Start Address
Bit 13 Start Address
Bit 12 Start Address
Bit 11 Start Address
Bit 10 Start Address
Bit 9 Start Address
Bit 8
REG[12h] Screen 1 Display Start Address 2
n/a n/a n/a n/a Start Address
Bit 19 Start Address
Bit 18 Start Address
Bit 17 Start Address
Bit 16

Table 4-1: Number of Pixels Panned Using Start Address

Color Depth (bpp) Pixels per Word Number of Pixels Panned
116 16
28 8
44 4
82 2
15 1 1
16 1 1
REG[18h] Pixel Panning Register
Screen 2
Pixel Pan
Bit 3
Screen 2
Pixel Pan
Bit 2
Screen 2
Pixel Pan
Bit 1
Screen 2
Pixel Pan
Bit 0
Screen 1
Pixel Pan
Bit 3
Screen 1
Pixel Pan
Bit 2
Screen 1
Pixel Pan
Bit 1
Screen 1
Pixel Pan
Bit 0

Table 4-2: Active Pixel Pan Bits

Color Depth (bpp) Pixel Pan bits used
1bits [3:0]
2bits [2:0]
4bits [1:0]
8bit 0
15/16 ---