AMD Geode LX 800@0.9W - Manual (Page 492)

492 AMD Geode™ LX Processors Data Book
Video Input Port Register Descriptions 33234H
6.10.2.3 VIP Status (VIP_STATUS)
VIP Memory Offset 08h
Type
R/W
Reset Value xxxxxxxxh
VIP_STATUS Register Map
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
APC
RS
V
D
FPE
RS
V
D
DPC
SO
BRNU RS
V
D
MS
G_BERR
B2_F
ULL
B1_F
ULL
RSVD
GL
W
C
FE
RSVD F V
R
UN_ST
A
T
US
VIP_STATUS Bit Descriptions
Bit Name Description
31:24 APC (RO) Ancillary Packet Count (Read Only). Number of ancillary packets available in the ancil-
lary buffer in system memory. This count is incremented each time an ancillary packet is
received. It gets decremented when a 1 is written to the DPC bit (bit 18).
23 RSVD Reserved.
22:20 FPE (RO) FIFO Pointer Error (Read Only). These bits indicate if the FIFO pointers are misaligned
at the point when the base registers are updated. A 1 indicates that the pointers may be
misaligned, which could result in an horizontal image shift. These bits are valid only when
VBI data reception is disabled. INT15 is generated when any of these bits go active.
[22] - B FIFO.
[21] - R FIFO.
[20] - Y FIFO.
19 RSVD Reserved.
18 DPC (WO) Decrement Ancillary Packet Count (Write Only). Writing a 1 to this bit causes the
ancillary packet count to be decremented by 1.
17 SO (WO) Sync Out (Write Only). Writing a 1 to this bit causes a 0-1-0 transition on the
VIP_VSYNC pin (32 GLIU clocks).
16 BRNU (RO) Base Register Not Updated (Read Only).
0: All base registers are updated.
1: One or more of the base registers have been written but have not yet been updated.
Note: The following base registers are updated at a start-of-frame event.
TASK_A_VID_EVEN_BASE, TASK_A_VID_ODD_BASE, TASK_A_VBI_EVEN_BASE,
TASK_A_VID_ODD_BASE, TASK_A_VID_EVEN_BASE, TASK_A_VID_ODD_BASE,
TASK_A_VBI_EVEN_BASE, TASK_A_VID_ODD_BASE
The start-of-frame event occurs when entering a vertical blanking interval during the Odd
field (for interlaced video) or when entering any vertical blanking interval (non-interlaced
video). Since the base pointers are initialized to 0 at reset, a start-of-frame event MUST
occur before enabling VIP to receive data. Otherwise, VIP will save the first video frame
to address 0 in system memory. One way of insuring this is to initialize VIP to receive
video data with the RUN_MODE bits (VIP Memory Offset 00h bits [7:5]) set to 0. This
enables the VIP input interface, but it will not capture video. Poll this bit until the internal
base register updates have occurred. The RUN_MODE control can then be programmed
to start capturing data on the next line/field/frame boundary.
15 RSVD Reserved.