Multi-Standard ADPCM (CS4110, CS4120, CS4125, CS4180)
Features
- Fully compliant with International Telecommunications Union (ITU) standards G.721, G.723, G.726, G.726a, G.727, and G.727a
- Supports large number of simultaneous channels:
- CS4110: 8 duplex/16 simplex
- CS4120: 32 duplex/64 simplex
- CS4125: 64 duplex/128 simplex
- CS4180: 384 duplex/768 simplex
- Burst mode or continuous operations
- Online configurable for different compression rates, µ-law or A-law, for each encoding or decoding channel
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Block Diagram
Figure 1 shows the motion JPEG decoder block diagram.
| Figure 1. Block Diagram |
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Description
The Amphion CS4100 family of adaptive differential pulse code modulation (ADPCM) cores is designed to provide high-performance solutions for a broad range of applications requiring speech compression and decompression. On Altera® devices, these ADPCM cores support up to 384 duplex channels, each of which is independently selectable for encoding or decoding, and are fully compliant with the ITU G.726, G.726a, G.727, and G.727a standards. The ADPCM cores are capable of processing both burst and continuous data streams, with the flexibility to assign any channel to encode or decode arbitrarily. The implementation is low latency (ranging from one clock cycle in the CS4180 to 16 clock cycles in the CS4110-CS4125) and the simple core interface allows easy integration into larger systems.
The Amphion ADPCM cores consist of 5 primary sections: an ADPCM transcoding engine, logarithmic pulse-code modulation (PCM)/uniform PCM expander, uniform PCM/logarithmic PCM compressor, channel configuration and control, and coding states storage memory, as shown in Figure 1. The core operates on one input sample at a time, using one or 16 clock cycles(1) to complete the encoding or decoding. Multichannel coding is implemented on a time-multiplexing basis. Input/output channel multiplexing and serial to/from parallel conversion circuitry may be added to suit the target system as required.
The CS4100 series of cores have two channel addressing modes: a flexible mode and a duplex mode(2). In the duplex mode, half of the channels are set to encode and half to decode. The flexible mode allows each channel to be set, and reset, individually. Within each of these modes the core can encode data from three types of PCM formats, as specified by ITU standard G.711, to 2-, 3-, 4-, or 5-bit ADPCM format. These are 8-bit µ-law uniform PCM or 13-bit A-law uniform PCM. The core can also decode data from the 2, 3, or 5-bit ADPCM format to the three types of PCM format.
The cores are on-line configurable in terms of compression rate and PCM law(3), and allow on-the-fly selection of PCM/uniform PCM input/output. Each member of Amphion's ADPCM family has been tested and verified to be fully compliant using the ITU standard test vectors.
Applications for the CS4100 family of ADPCMs include:
- Wireless telecommunications
- DECT phones
- Digital cellular
- Satellite communications
- Wired telecommunications
- Videoconferencing
- Voicemail systems
- Private branch exchanges (PBXs)
Notes:
- 16 clock cycles in the CS4100-25 cores, one clock cycle in the CS4180.
- The CS4180 operates in the flexible mode only.
- Compression rate and PCM law are selected on-the-fly in the CS4180.
Device Utilization Example
Table 1 lists the typical device utilization results for the ADPCM Speech Coder.
| Table 1. Typical Device Utilization |
| Amphion Product ID |
Device |
Speed Grade |
Utilization |
Performance
(fMAX) |
Data Throughput
(Msamples/sec) |
| Logic Cells |
ESBs (1) |
| CS4110AA |
EP20K300E |
8 |
-1 |
4,249 |
11 |
21.90 MHz |
Contact Amphion |
| CS4120AA |
EP20K300E |
32 |
-1 |
4,302 |
14 |
22.50 MHz |
Contact Amphion |
| CS4125AA |
EP20K300E |
64 |
-1 |
4,307 |
18 |
20.10 MHz |
Contact Amphion |
| CS4125AA |
EP1K100F |
64 |
-1 |
3,888 |
9 |
21.83 MHz |
Contact Amphion |
| CS4180AA |
EP20K1000E |
384 |
-1 |
6,110 |
149 |
6.36 MHz |
Contact Amphion |
Notes:
- ESBs = Embedded system blocks
Contact Information
For additional information, you can contact Amphion Semiconductor, Ltd. at:
Headquarters and Engineering:
Amphion Semiconductor, Ltd.
51 Malone Road
Belfast, BT9 6RY
Northern Ireland
Tel. +44 28 9050-4000
Fax +44 28 9050-4001
Email: info@amphion.com
URL: http://www.amphion.com
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