AMD Geodeā„¢ LX Processors Data Book 345
Display Controller Register Descriptions 33234H
6.6.11.2 DC VBI Odd Control (DC_VBI_ODD_CTL)
Settings written to this register do not take effect until the start of the following frame or interlaced field.
6.6.11.3 DC VBI Horizontal Control (DC_VBI_HOR)
Settings written to this register do not take effect until the start of the following frame or interlaced field.
28 VBI_ENA VBI Enable. Setting this bit to 1 enables VBI (Vertical Blank Interrupt) data. This is a data
stream that is placed in the off-screen region at the start of each field. This data is passed
through the graphics output path, but is not filtered or modified in any way.
27:0 VBI_EVEN_
OFFSET
VBI Even Address Offset. Indicates the starting offset for VBI data for even fields. This
address must be QWORD aligned; the low three bits are always 0. If interlacing is dis-
abled, this offset is used for VBI data.
DC Memory Offset 0A4h
Type R/W
Reset Value xxxxxxxxh
DC_VBI_EVEN_CTL Bit Descriptions (Continued)
Bit Name Description
DC_VBI_ODD_CTL Register Map
313029282726252423222120191817161514131211109876543210
RSVD VBI_ODD_OFFSET 0
DC_VBI_ODD_CTL Bit Descriptions
Bit Name Description
31:28 RSVD Reserved. Set to 0.
27:0 VBI_ODD_
OFFSET
VBI Odd Address Offset. Indicates the starting offset for VBI data for odd fields. This
address must be QWORD aligned; the low three bits are always 0. If interlacing is dis-
abled, the even offset is used for VBI data.
DC Memory Offset 0A8h
Type R/W
Reset Value xxxxxxxxh
DC_VBI_HOR Register Map
313029282726252423222120191817161514131211109876543210
RSVD VBI_H_END RSVD VBI_H_START
DC_VBI_HOR Bit Descriptions
Bit Name Description
31:28 RSVD Reserved. Set to 0.
27:16 VBI_H_END VBI Horizontal End. Specifies the horizontal end position for VBI data minus 1 pixel.
15:12 RSVD Reserved. Set to 0.
11:0 VBI_H_START VBI Horizontal Start. Specifies the horizontal start position for VBI data minus 1 pixel.