
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 21: MPEG-1 and MPEG-2 Variable Length Decoder
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
21-16
5.3 Register Table
0x07 501C
VLD_INP_ADR
VLD Input Memory Address
0x07 5020
VLD_INP_CNT
VLD Input Count gives the number of bytes to be read from main memory
0x07 5024
VLD_MBH_ADR
VLD Macroblock Header Writeback Address
0x07 5028
VLD_MBH_CNT
VLD Macroblock Header Writeback Count
VLD_RL_ADR
VLD Run-level Writeback Address
0x07 5030
VLD_RL_CNT
VLD Run-level Writeback Count
0x07 5034
VLD_BIT_CNT
VLD Bit Count gives the number of bits consumed by the VLD
0x07 5200
MC_PICINFO0
Macro-block height
0x07 5FF4
PD
Power Down Register
0x07 5FFC
MODULE ID
Module Identication Register
Table 9:
Register Summary …Continued
Offset
Symbol
Description
Table 10: VLD Registers
Bit
Symbol
Acces
s
Value
Description
Offset 0x07 5000
VLD_COMMAND
31:12
Reserved
R
11:8
Command
R/W
0
Command code of the VLD command to be executed
0x1 = Shift Bitstream by “Shift Count” bits
0x2 = Parse Macroblock
0x3 = Search for next Start Code
0x4 = Reset Variable Length Decoder
0x5 = Initialize VLD
0x6 = Search for the Start Code given in bits [7:0].
0x7 = Parse Macroblock Row
0x8 = Flush Write FIFOs
0x9 = Parse Long
7:0
Mblock/Shift Count or
start code
R/W
0
For the ‘Shift Bitstream’ command, only the lower 4-bit are used; the
upper 4-bit should be set to 0. All 8 bits are used for the ‘Parse
macroblocks’ and ‘Search for given start code’ commands. For
Parse Long command these bits cannot be programmed to 0.
Offset 0x07 5004
VLD_SR
31:15
Reserved
R
15:0
Shift Register
R
NI
This register is a shadow of the VLD’s operational shift register and
it allows the DSPCPU to access the bitstream through the VLD. Bits
15 through 0 are the current contents of the VLD shift register.
Offset 0x07 5008
VLD_QS
31:5
Reserved
R
4:0
Quant scale
R/W
NI
This register contains the quantization scale code to be output by
the VLD until it is overridden by a macroblock quantizer scale code.
The quantizer scale code is part of the macroblock header output.
Offset 0x07 500C
VLD_PI