Figure 7-4. Vip Block Diagram - AMD Geode SC3200 Data Book

Video Processor Module
7.2.1 Video Input Port (VIP)
The VIP block is designed to interface the SC3200 with
external video processors (e.g., Philips PNX1300 or Sigma
Designs EM8400) or external TV decoders (e.g., Philips
SAA7114). It inputs CCIR-656 Video and raw VBI data
sourced by those devices, decodes the data, and delivers
the data directly to the Video Formatter (Direct Video
mode) or to the GX1 module's video frame buffer (Capture
Video/VBI modes). Figure 7-4 shows a diagram of the VIP
block.
From the VIP block's perspective, Direct Video mode is
always on. There are no registers that enable/disable
Direct Video mode. The data source selected at the video
mux (F4BAR0+Memory Offset 400h[1:0]) determines if the
data from the VIP interface is moved directly or must be
captured.
Two FIFOs in the VIP block support the efficient movement
of Video and VBI data. For Capture Video/VBI modes, a
128-byte FIFO buffers both Video and raw VBI data pro-
cessed by the CCIR-656 decoder. For Direct Video mode,
there is a 2048-byte FIFO that buffer the CCIR-656
decoder's video data. The FIFOs are also used to provide
clock domain changes. The VIP interface clock (nominally
27 MHz) is the input clock domain for both FIFOs. For the
Capture Video/VBI FIFO, the data is clocked out using the
FPCI clock (33 or 66 MHz). For the Direct Video FIFO, the
VSYNC
VIP_VSYNC
VIP
Data
CCIR-656
Decoder
VIP
Clock
AMD Geode™ SC3200 Processor Data Book
Stop DCLK
GenLock
Control
Capture Video/VBI
Controller and
Bus Master
Fast-PCI Clock
Capture Video/VBI
Capture Video/VBI Data
FIFO
GX1 Video Clock
Direct Video
Direct Video Data
FIFO
F4BAR2
Direct Video/VBI
Controller
Registers

Figure 7-4. VIP Block Diagram

Video data is clocked out using the GX1's Video port clock
(75, 116, or 133 MHz GX1 core clock divided by 2 or 4).
7.2.1.1 Direct Video Mode
As stated previously, Direct Video mode is on by default so
no registers need to be programmed to support this mode
other than to select the direct video data at the video mux.
The video mux control register is located at F4BAR0+Mem-
ory Offset 400h[1:0].
Direct Video mode while supported is not an optimal mode
of operation. This mode supports only one vertical resolu-
tion and refresh rate, which is that of the incoming data.
Horizontal resolution can be scaled if desired. Since the
incoming data has odd and even fields, incoming line must
be doubled for it to display properly. This is equivalent to
the Bob technique which is explained later in this section.
GenLock
Because video input data from the VIP is sent directly, with-
out significant buffering frame-to-field synchronization is
required with the GX1 module's graphics data. This syn-
chronization is known as GenLock. The GenLock registers
are located at F4BAR0+Memory Offset 420h and 424h.
Control
VIP
32581C
Fast
X-Bus
Fast-PCI
GX1
to
Module
Fast-PCI
Bridge
Video or VBI Data
to Video
Formatter
Video
Mux
313