PM-36 (JPEG Compression)

JPEG Image Processor

An ISO standard for lossy image compression, JPEG can reduce the size of image data without a noticeable difference in image quality. This improves system performance of peripheral-based applications by reducing bandwidth and storage requirements. The PM-36 is ideal for high resolution imaging applications such as copiers, scanners, printers and multifunction peripherals, particularly in networked environments.
 

Benefits

  • High Performance-JPEG Imaging Codec-Delivers sustained data rates of up to 110 MB per second
  • Efficient Coding-four loadable Q-Tables and two loadable Huffman table pairs
  • Highly Integrated-Internal Phase-Locked Loop (PLL)
  • 3.3 Volt supply-5 Volt Tolerant I/O
  • Standard Compliant-ISO IS 10918-1/10918-2
  • High Throughput

    The PM-36 can sustain data rates of 80 or 110 MB per second to support real time operations. In addition, it implements two advanced features that maximize throughput and system performance:
  • Programmable code rate control-This optional mode limits the encoded output data bandwidth to a predefined rate by dynamically reducing the quantization accuracy on a block-byblock basis, as required. This assures maximum throughput in high-speed peripherals.
  • Programmable code size control-This mode allows definition of an upper limit for the size of the encoded output file so that it does not exceed a fixed memory buffer size. This is achieved in a single pass of the data, with no degradation in performance.
  • Efficient Coding

    The PM-36 features several advanced JPEG coding techniques for improved efficiency. Four loadable Q-tables are available for dynamic quantization control on a block-by-block basis. In addition, The PM-36 contains two loadable Huffman table pairs, which improves coding efficiency by allowing the system to use different encoding factors with out reprogramming the device.

    Highly Integrated

    The PM-36 features an internal Phase-Locked Loop (PLL) that enables the chip to generate its main internal clock frequency from a lower-frequency signal. This reduces emissions and simplifies board design, particularly in systems using low-power CPUs and no external SRAM.

    PM-36 Capabilities

    The PM-36 enables the following combinations of operations to be performed on the data stream during one pass through the device:

  • Raster format image data: Converted to Block mode, subsampled 2:1, and JPEG encoded
  • Block format image data: JPEG encoded
  • JPEG-encoded data: JPEG decoded to raw format, upsampled 2:1, and output in Block or Raster format
  • Design Considerations

    The PM-36 can be easily integrated into a variety of systems. Design features include:
  • A simple peripheral interface for use with any standard processor
  • Programmable control port bus width (16 or 32 bits)
  • Flexible input and output ports, which simplify system design
  • Input and output ports can be sized at 8, 16, 24, or 32 bits wide and contain bit, byte and word order controls to match any processor bus requirements
  • 256-byte buffer on both input and output ports can minimize or even eliminate external buffering requirements
  • High speed I/O modes, synchronous FIFO and Burst DMA modes
  • The PM-36 requires little in the way of external support chips. A minimal system requires only a frequency source. An external SRAM array (up to 4 MB) may be added to enable raster format data streams. The external SRAM is used to store input or output lines for raster-to-block or block-to-raster conversion operations

    Key Features

  • Conforms to ISO IS 10918-1/10918-2 JPEG baseline for grayscale and color
  • 80 MHz clock speed for sustained 80 MB/second throughput (Raster or Block mode operations)
  • 110 MHz clock speed for sustained 110 MB/second throughput (Block mode operations only)
  • 3.3 Volt power supply
  • Four selectable quantization tables
  • Two pairs of loadable Huffman tables
  • Programmable code rate control
  • Programmable code size control (single pass)
  • Raster and block data formats
  • Internal 256-byte buffers on input and output ports
  • I/O modes supporting transfer rates up to 40 MHz (280 MB/per second)
  • Internal Phase-Locked Loop (PLL)
  • Horizontal 2:1 subsampling and upsampling support for 4:2:2 formats using 2 or 3 point filters (Raster mode operations only)
  • PM-36 Specifications

  • Formats Supported
  • Grayscale pixels in Raster or Block format (8 bits per pixel)
  • Color pixels in Raster or Block format (8 bits per component)
  • JPEG-encoded data
  • Electrical Specification

  • 3.3 Volt power supply
  • 5 Volt tolerant I/O (TTL-compatible I/O)
  • Designed and fabricated in 0.35 micron standard cell technology
  • Available industry-standard 208 PQFP package with 0.5 mm lead spacing
  • Also available in lead-free “green” packaging
  • PM36 Block Diagram

    PM36 Block Diagram (GIF)