348 AMD Geodeā„¢ LX Processors Data Book
Display Controller Register Descriptions
33234H
6.6.12.2 DC Color Key Mask (DC_CLR_KEY_MASK)
6.6.12.3 DC Color Key Horizontal Position (DC_CLR_KEY_X)
Settings written to this register do not take effect until the start of the following frame or interlaced field.
6.6.12.4 DC Color Key Vertical Position (DC_CLR_KEY_Y)
Settings written to this register do not take effect until the start of the following frame or interlaced field.
DC Memory Offset 0BCh
Type R/W
Reset Value 00xxxxxxh
DC_CLR_KEY_MASK Register Map
313029282726252423222120191817161514131211109876543210
RSVD CLR_KEY_MASK
DC_CLR_KEY_MASK Bit Descriptions
Bit Name Description
31:24 RSVD Reserved. Set to 0.
23:0 CLR_KEY_
MASK
Color Key Mask. This field is ANDed with both the pixel and the color key value (in
DC_CLR_KEY, DC Memory Offset 0B8h[23:0]) before comparing the values. This allows
the value of some bits to be ignored when performing the match.
DC Memory Offset 0C0h
Type R/W
Reset Value 00000000h
DC_CLR_KEY_X Register Map
313029282726252423222120191817161514131211109876543210
RSVD CLR_KEY_X_END RSVD CLR_KEY_X_START
DC_CLR_KEY_X Bit Descriptions
Bit Name Description
31:27 RSVD Reserved. Set to 0.
26:16 CLR_KEY_X_
END
Color Key Horizontal End. This field indicates the horizontal end position of the color
key region minus 1.This represents the first pixel past the end of the color key region.
This field is 0-based; the upper left pixel of the screen is represented by (0,0).
15:11 RSVD Reserved. Set to 0.
10:0 CLR_KEY_X_
START
Color Key Horizontal Start. This field represents the horizontal start position of the color
key region minus 1. This represents the first pixel within the color key region.
DC Memory Offset 0C4h
Type R/W
Reset Value 00000000h
DC_CLR_KEY_Y Register Map
313029282726252423222120191817161514131211109876543210
RSVD CLR_KEY_Y_END RSVD CLR_KEY_Y_START