Silicon Imaging , Inc. 2004 Page 18 of 39 Company Confidential
Window Programming – Image Size & Position
Register
Name
Default
Description
0x01
Row Start
0x0014
(20)
First row to be read out + 20. (Bits 10~0)
Note: Register value must be an even number.
0x02
Column Start
0x0020
(32)
First column to be read out + 32. (Bits 11~0)
Note: Register value must be an even number. If column bin is
enabled, the value must be a multiple of Reg0x23 [5-4] + 1.
0x03
Height
0x05FF
(1535)
Number of rows – 1. Min = 0x0001. (Bits 10~0)
Note: Register value must be an odd number.
0x04
Width
0x07FF
(2047)
Number of columns – 1. Min = 0x0001. (Bits 10~0)
Note: Register value must be an odd number.
The minimum value for Reg0x03 is 0x0001; for Reg0x04, 0x0001. Thus, the smallest window size is two columns by
two rows (2H x 2V). The value of Reg0x03 and Reg0x04 must be an odd number (there can only be even number of
columns).
The user can program the window size to be any format
desired. To place a 1280 x 1024 window at a start position
of 640, 480, use the following commands:
ly 04 xxxx Set
WIDTH
to (1280 - 1) = 1279
(0x04ff)
ly 03 xxxx Set
HEIGHT
to (1024 -1) = 1023
(0x03ff)
ly 02 xxxx Set
COLUMN_START to 640+32=672 (0x02a0)
ly 01 xxxx Set
ROW_START to 480+20=500
(0x01f4)
As shown in the adjacent picture, Registers 4 and 3 set the
size of the display window. Register 2 sets the column start
location and registers 1 set the row start location.
Note: Other custom commands can be used to move the
window at high speeds – please consult the factory.
The following table shows examples of register settings to achieve various resolutions and frame rates based on a
nominal
48MHz
clock rate.
For tables above, the settings for Reg0x05 (horizontal blanking) and Reg0x06 (vertical blanking) are 21 and
15 respectively, while all of the registers are set to default.
