Video Decoder Registers
4-39
Pack Pause
W 1
When this bit is set by the host, the stream parser in the
device pauses after the last pack header data is
completely stored in the SDRAM buffer assigned to it.
This function is designed especially for use with the
Force Sequence End Code feature (Register 123, bit 2)
and the Flush Audio feature (Register 123, bit 3). The
stream parser stops at the next pack header boundary.
Force Sequence End Code
R/W 2
When this bit is set, the stream parser forces a Video
Sequence End Code into the video channel just before
the next Navi pack boundary if the Navi Pause bit is set
and/or just before the pack header boundary if the Pack
Pause bit is set. Note that the Sequence End Code is
followed by 504 bits (63 bytes) of all zeros. This acts as
stufng and helps ush all the video data from the
channel into the video decode pipeline.
Flush Audio
R/W 3
When this bit is set, the stream parser forces 120 bits (15
bytes) of all zeros into the Audio ES channel buffer just
before the next Navi pack boundary if the Navi Pause bit
is set and/or the next Pack Header boundary if the Pack
Pause bit is set. This acts as stufng and helps ush all
the audio data from the channel into the audio decode
pipeline.
Navi Pack Counter Enable
W 4
When this bit is set, the Navi pack counter is enabled.
The stream parser checks the counter before storing the
next Navi pack. If the counter indicates that 0 or 1 Navi
pack has been stored by the stream parser but not yet
read by the host (counter values 0 or 1), the stream
parser still reads the next Navi pack. When the counter
indicates that there are two Navi packs stored but not
read by the host (counter value 2), the stream parser
pauses at the next Navi pack start point. At this point, the
stream parser expects the host to read a Navi pack from
the DSI channel in SDRAM and decrement the counter
by writing to Register 123, bit 5, before storing the next
Navi pack. Thus, the Navi Pack Counter Enable function
ensures that no Navi packs are lost, i.e., not read by the
host before being overwritten by the next Navi pack. The
DSI channel should be programmed to a size that will
accommodate information from at least two Navi packs.