zr36067 ETC-unknow, zr36067 Datasheet - Page 21

• Manufacturer Part Number: zr36067
• Description: Av Pci Controller
• Manufacturer: ETC-unknow

mand” information, written by the host, for the next available
b u f f e r . T a b l e 1 0 s h o w s t h e i n t e r p r e t a t i o n f o r t h i s
c a s e .
Table 10: STAT_COM entry content, when
STAT_BIT=0
If the STAT_BIT=‘1‘, the content of the entry is the “status” infor-
mation, written by the ZR36067, of the most recently processed
field or frame. Table 11 shows the interpretation for this case.
Table 11: STAT_COM entry content, when
STAT_BIT=1
9.2 Fragment Table
The Fragment Table (Figure 9) defines the structure of the allo-
cated memory for each code buffer. The table has N entries for
N allocated fragments. Each entry holds two doublewords:
31:2
• first doubleword - the physical address of the fragment (must
• second doubleword - has the following fields:
31:24
22:1
Bit
Bit
23
1
0
0
be doubleword aligned).
- bits 20:1, the fragment length in doublewords (the frag-
- bit 0, F (“Final” bit), when ‘1’ indicates that this fragment is
- bits 31:21, unused, must be 0.
ment must be doubleword aligned),
the final fragment of the buffer,
FRAG_TAB_PTR[31:2]
FRAG_TAB_PTR [1]
STAT_BIT
F_CNT[7:0]
F_LENGTH[21:0]
STAT_BIT
Content
Content
The serial number, modulo 256, of the
The length of the most recently com-
most recent field or frame. Used in
compression only.
Reserved, set to ‘0’.
pressed field or frame in bytes, used in
compression only. The length is dou-
bleword aligned, so bits 2..1 are
always ‘0‘.
‘1‘, indicating that this table entry is a
status written by the ZR36067.
The address pointer to the
fragment table of the next buffer
to be used. The 2 l.s. bits of the
address must be ‘0’ - that is, the
address must be doubleword
aligned.
Must to be ‘0‘.
Must be ‘0’ to indicate that the
table entry is a command.
Description
Description
21
9.3 JPEG Compression Modes
The sequence of actions performed by the host software and the
ZR36067 is as follows:
Several scenarios might cause a field or frame process to be
unsuccessful:
After an unsuccessful field/frame process in compression, the
ZR36067 does not issue an interrupt, re-uses the current code
buffer - that is, does not over-write its STAT_COM entry, and
restarts with the next field or frame. The software can determine
the number of fields or frames that were skipped by reading
F_CNT.
9.4 JPEG Decompression Modes
The sequence of actions performed by the host software and the
ZR36067 is as follows:
• The host allocates the first four code buffers and writes out
• The host loads the ZR36067’s I_STAT_COM_PTR register
• After the start of the compression process, the ZR36067
• After successfully completing transfer of the compressed
• If a new code buffer is unavailable at the beginning of a field
• When the host receives the interrupt, it checks the
• The allocated code buffer memory was smaller than the ac-
• A ZR36060 strip memory overflow occurs during the field/
• The compression of a field has not ended by the time the
• The host allocates the first four code buffers and writes out
the code buffer table and the fragment table.
with the base address of the code buffer table.
starts filling the fragments of the first code buffer with the
compressed data of the first field or frame.
data of a field or frame, the ZR36067 writes the status infor-
mation back to the STAT_COM entry of the current buffer. It
sets the STATUS_BIT in the STAT_COM entry, declaring its
content as status. It then issues an interrupt, and starts the
next field or frame process.
or frame process (that is, if the STATUS_BIT of the next
buffer entry is ‘1’), the ZR36067 polls the STAT_COM entry
until the buffer is available.
STAT_COM entries in the code buffer table. For each entry
whose STAT_BIT=’1’, the host checks F_CNT to determine
whether any fields/frames were dropped. It records the code
buffer information, updates the fragment table and
STAT_COM entry of the code buffer, and returns it by reset-
ting STAT_BIT to ‘0’.
tual field/frame code volume (the ZR36067 fills the final
fragment, but the field/frame code transfer is not complete).
frame compression (might be caused by very large PCI bus
latency).
trailing edge of the next VSync is detected.
the code buffer table and the fragment table.
AV PCI CONTROLLER