Datenblatt-pdf.com


ZR36050PQC-27 Schematic ( PDF Datasheet ) - ETC

Teilenummer ZR36050PQC-27
Beschreibung JPEG IMAGE COMPRESSION PROCESSOR
Hersteller ETC
Logo ETC Logo 




Gesamt 30 Seiten
ZR36050PQC-27 Datasheet, Funktion
ZR36050
ADVANCE INFORMATION
JPEG IMAGE COMPRESSION PROCESSOR
FEATURES
s Implements JPEG Baseline image compression and
expansion, including:
- DCT/IDCT operations
- Quantization
- Variable length coding/decoding
s Full support of the JPEG Baseline standard, including:
- Bit and byte stuffing
- JPEG markers including restart (RST), application (APP),
and comment (COM)
s JPEG Lossless compression and expansion
s DMA/SLAVE bus interface
s Motion video (30 frames/sec) compression/expansion
capability for CCIR resolution (720 x 480)
s “Fast Preview” option
- Preview of “thumbnail” version of images (up to 25x faster)
s Bit rate control option
- Guarantees compressed image file size
s Low cost solution
- Low cost single chip
- Support for inexpensive memories
- Requires minimal host intervention
s TTL compatible
s 27 and 21 MSamples/sec data-rate
s Standby mode for very low power consumption
s 100-pin plastic quad flat-pack (PQFP) packaging
APPLICATIONS
s Computer and multimedia add-in boards
s Full-motion video compression/expansion
s Digital still cameras and peripherals
s Security and industrial systems
s Videophones and color FAX machines
s Color printers and scanners
s Fixed bit rate image transmission devices
s Cost-sensitive image compression systems
GENERAL DESCRIPTION
The ZR36050 is a high-speed JPEG Image Compression Pro-
cessor that performs the algorithm specified by the JPEG
Baseline and JPEG Lossless standards for high-quality image
compression and expansion of continuous-tone color or mono-
chrome images. The ZR36050 performs Discrete Cosine
Transform (DCT), quantization and variable-length encoding for
image compression (coding), and the corresponding inverse
operations for expansion (decoding).
In the JPEG Baseline encoding operation, the ZR36050
performs the DCT operation on 8 x 8 blocks of image data, con-
verting image data into its spatial frequency components, and
quantizes them using a user defined “quantization table.”
Because the human visual system is less sensitive at the higher
spatial frequencies, these higher frequency components can be
quantized more coarsely than the lower-frequency components,
with negligible effect on image quality.
The coarser quantization of high-frequency coefficients results in
long strings of zero valued quantized coefficients, when the 8x8
blocks are scanned in zigzag order. The scanned coefficients
are characterized in terms of their nonzero values and the zero
run lengths. As a result, a long string of zeroes is coded as a
single number. The ZR36050 then performs Huffman coding
using user-defined Huffman tables, whereby bit patterns of dif-
ferent lengths code the nonzero values (values that occur
frequently use the shortest codes; while those that infrequently
occur use the longest codes). These techniques greatly reduce
the amount of memory needed to store an image.
In the decoding operation, the compressed data is decoded (the
inverse of the Huffman and the zigzag modified-run-length
coding), and dequantized. A 2-D inverse Discrete Cosine Trans-
form is performed on the DCT coefficients, resulting in an
expanded image.
+5V
PIXEL
Interface
Control
DCT
Coefficient
Output
Clock
12
PIXEL
8
CODE
DSYNC
EOS
STOP
COMP
RESET
STDBY
FREEZE
ZR36050
END
2 CL
JPEG IMAGE
COMPRESSION
PROCESSOR
CLKEN
11
COEF
CSYNC
CLK_IN
VSS
COE
CWE
CCS
CAEN
CBUSY
DATA
ADDR
RD
WR
CS
INT
DINT
DREQ
DACK
8
10
Compressed
Data Interface
Host Interface
Figure 1. ZR36050 Logical Pinout
ZORAN Corporation s 1705 Wyatt Drive s Santa Clara, CA 95054 s (408) 986-1314 s FAX (408) 986-1240
August 1993
This document was created with FrameMaker 4.0.4






ZR36050PQC-27 Datasheet, Funktion
ADVANCE INFORMATION
ZR36050
Table 1. Signal Description1, 2 (Continued)
Type3
Signal
Encode Decode
Description
CBUSY
I I Compressed Data Memory Busy. This active-low input signal indicates that the Compressed Data
Memory is busy. During the encoding modes, CBUSY active means that the ZR36050 cannot write
to the Compressed Data Memory. During the decoding modes, CBUSY active means that the
ZR36050 cannot read from the Compressed Data Memory.
If CBUSY is activated at least one CLK_IN prior to the beginning of a read or write cycle, then the
next read or write cycle will not be performed. The minimum width of CBUSY is one CLK_IN cycle.
ADDR(9-0)
I I Internal Memory Address. This 10-bit input bus is used to address the Internal Memory of the
ZR36050.
DATA(7-0)
B B Internal Memory Data Bus. This 8-bit bidirectional bus is used to read from or write to the Internal
Memory of the ZR36050. In the 16-bit Slave and DMA modes, the CODE bus is used as an extension
of the DATA bus.
RD I I Read. This active-low input signal acts as a read pulse from the host to the ZR36050.
WR I I Write. This active-low input signal acts as a write pulse from the host to the ZR36050.
The DATA bus is latched on the rising edge of WR.
CS I I Chip Select. This active-low input signal acts as a chip select signal from the host to the ZR36050.
INT O O Interrupt. This active-low output signal notifies the host that one of the STATUS bits, except for
DATRDY, is set. INT is reset by reading the relevant STATUS register, by activation of RESET, or by
a GO command.
DINT
O O Data Ready Interrupt. In Slave mode Compressed Data Transfer, this active-low output signal notifies
the host that the DATRDY bit in the STATUS_1 register is set. DINT is reset by reading the
STATUS_1 register, by activation of RESET, or by reading or writing the compressed data in the
Compressed Data Input/Output register at address 30H of the ZR36050 Internal Memory with CS
active.
DACK
I I DMA Acknowledge. This active-low input signal is used in DMA mode Compressed Data Transfer.
DACK is an acknowledgment pulse from the DMA controller to the ZR36050. It must be active during
the entire Read or Write cycle.
DREQ
O O DMA Request. This active-low output signal is used in DMA mode Compressed Data Transfer. DREQ
is the DMA request from the ZR36050 to the host. The ZR36050 does not output a DREQ until the
DACK signal to the previous DREQ has been deactivated.DREQ is deactivated by RESET, or by
DACK.
COMP
O O Compress/Expand. This output signal provides an indication of the current operating mode of the
ZR36050. When it is high, the ZR36050 is in the encoding mode; when it is low, the ZR36050 is in
the decoding mode. The mode and the state of COMP are changed when the MODE register in the
Internal Memory is read by the ZR36050 after a GO command is issued by the host. One CLK_IN
cycle after COMP changes state, EOS, STOP, and DSYNC change directions. Activation of RESET
sets COMP high.
1. The DATA, CODE, PIXEL, and COEF buses have internal pull-downs that provide 50 microamps of pull-down current at 0.4 volts.
2. The control pins: DSYNC, EOS, STOP, END, CL, CSYNC, COE, CWE, CCS, CAEN, INT, DINT, DREQ and COMP, have internal pull-up
devices that provide 50 microamps at 2.4 volts. These pull-ups are turned on only when STDBY is active but RESET is inactive. When STDBY
is active together with RESET, the above control pins float.
3. I = Input, O = Output, B = Bidirectional, S = Supply.
6

6 Page









ZR36050PQC-27 pdf, datenblatt
ADVANCE INFORMATION
ZR36050
Baseline Compression Pass, and the resulting compressed data
is fully JPEG compatible. At the completion of the Compression
Pass with or without Bit Rate Control, the ZR36050 calculates a
New Scale Factor (NSF) and saves it in the SF Internal Memory
register. The NSF can be used in the next encoding operation or
the host can overwrite it by its own Scale Factor.
Auto Bit Rate Control
In this mode the ZR36050 performs a Statistical Pass followed
automatically (without host intervention) by a Compression Pass
with Bit Rate Control. The ZR36050 computes the new Scale
Factor and the Allocation Factor at the end of the Statistical
Pass, and rescales the quantization tables by the new scale
factor at the start of the Compression Pass. The DQT marker
must be enabled for Auto Bit Rate Control to work correctly.
Tables-Only Pass
In this mode, the ZR36050 generates compressed data in the
JPEG abbreviated format for table specification. The abbreviat-
ed format compressed data contains only the SOI marker,
quantization and/or Huffman tables specifications (DQT and/or
DHT marker segments), optional APP, COM marker segments,
and the EOI marker. The content of the MARKERS_EN register
specifies which marker segments are to be included in the
abbreviated format data. The Pixel Interface is inoperative in this
mode.
Tables Preload for Encoding
Prior to encoding a sequence of images with the same quantiza-
tion and/or Huffman tables, this mode is used to preload the
tables. The DQTI and DHTI bits of the MARKERS_EN register
specify which tables to preload. If DQTI is set, the ZR36050 mul-
tiplies the quantization tables, specified in the DQT segment of
Internal Memory by the Scale Factor, and stores the scaled
tables in the Quantization Tables Store. If DHTI is set, it decodes
the Huffman tables specifications from the DHT segment of
Internal Memory, where they are specified in accordance with
the JPEG syntax, and stores the decoded tables in the Huffman
Tables Store, for use in compressing the images. In this mode,
the Pixel Interface and the Code Buffer are inoperative.
JPEG Lossless Compression
In a Compression Pass, if the ZR36050 finds the SOF3 frame
marker in the Internal Memory, it switches to the JPEG Lossless
Compression mode. JPEG Lossless compression uses a spatial
algorithm, so the DCT Unit is bypassed in this mode. No quanti-
zation is performed, so the Quantization Tables Store is not
used. The ZR36050 encodes the image samples using the
JPEG one-dimensional horizontal prediction method and
Huffman coding. Up to two Huffman tables are allowed in JPEG
Lossless compression. The sample precision can be from 2 to 12
bits. Horizontally subsampled components are supported and no
point transform is performed (the point transform parameter in
the scan header marker segment is ignored).
DECODING MODES
JPEG Baseline Expansion
In Expansion mode, the ZR36050 reads compressed data and
expands it using the inverse of the JPEG Baseline encoding
algorithm. It stores the marker segments extracted from the com-
pressed data in the Marker Segments Section of Internal
Memory, where the host can access the information. When it
encounters a DQT or DHT marker segment, it decodes the
segment and stores the tables in the Table Stores. It expands
any subsequent compressed image data using the stored tables.
If the compressed data contains multiple instances of a marker
segment, a new segment will overwrite the previous segment of
the same type in the internal memory. This mode is also used to
decode abbreviated format tables-only compressed data.
Fast Preview
In this mode, the ZR36050 decodes only the DC coefficients
from the JPEG Baseline compressed image data, and outputs
them, after level-shifting to form unsigned DC values, via the
Pixel Interface. Since only one sample is output for each 8 x 8
block, the result is a thumbnail version of the image, scaled down
by a factor of eight horizontally and vertically. It is generated up
to 25 times faster than full image expansion. The inverse DCT
computation is bypassed in this mode.
Tables Preload for Decoding
The ZR36050 reads the quantization and/or Huffman tables from
Internal Memory and stores them in the Table Stores for
decoding images in the JPEG abbreviated data-only format. The
DQTI and DHTI bits of the MARKERS_EN register specify which
tables to preload. If DQTI is set, the ZR36050 multiplies the
quantization tables by the Scale Factor and stores the scaled
tables in the Quantization Tables Store. If DHTI is set, it decodes
the Huffman tables specifications from the DHT segment of the
Internal Memory, where they are specified in accordance with
the JPEG syntax, and stores the decoded tables in the Huffman
Tables Store. In this mode, the Pixel Interface and the Code
Buffer are inoperative.
JPEG Lossless Expansion
In Expansion mode, if the ZR36050 detects the SOF3 frame
marker in the compressed data, it switches to the JPEG Lossless
Expansion mode. The DCT Unit is bypassed in this mode, and
the quantization tables are not used. The compressed image is
decoded by the inverse of the method used in the Lossless Com-
pression mode. As in Lossless Compression, up to two Huffman
tables are allowed. The sample precision can be from 2 to 12
bits. Horizontally subsampled components are supported and no
point transform is performed (the point transform parameter in
the scan header marker segment is ignored. Therefore if a
lossless bitstream with point transform other than zero is input
into the ZR36050, it will be decoded as if the point transform is
zero).
12

12 Page





SeitenGesamt 30 Seiten
PDF Download[ ZR36050PQC-27 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
ZR36050PQC-21JPEG IMAGE COMPRESSION PROCESSORETC
ETC
ZR36050PQC-27JPEG IMAGE COMPRESSION PROCESSORETC
ETC

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche