Inverse Multiplexing for ATM (IMA) v1.0/1.1
Features
- Scalable design: supports a maximum of 32 Links/16 groups
- Flexible design: any link assigned to any group, or configured as pass through
- Shared architecture to minimize size
- All state machines implemented in hardware to minimize software interaction
- No software needed for operation other than configuration
- Configurable IMA frame length
- Configurable symmetrical/asymmetrical configuration and operation
- Supports common and independent transmit clock operation
- Implements the IMA Data Cell Rate (IDCR) specified by the ATM Forum
- Configurable link differential delay variation tolerance
- Supports internal or external delay cell buffers
- Reports anomalies (e.g., errored ICP cells, OIF) and defects (e.g., LIF, LODS).
- Maintains performance monitoring counters (e.g., ICP violation counts)
- Implements the test pattern procedure specified by the ATM Forum
- Programmable microprocessor interface compatible with Intel and Motorola microprocessors
- Can be used in conjunction with Modelware's Multi-Channel Transmission Convergence megafunction for applications requiring a transmission convergence function
- Supports group mapping to UTOPIA ports or to VPI/VCI bits
Block Diagram
Figure 1 shows the block diagram for a typical application of the IMA megafunction.
Figure 1. Block Diagram
Description
The IMA megafunction provides modular bandwidth, using existing physical links (e.g., DS1/E1, JT2, DS3/E3), to access ATM networks and to interconnect ATM network elements. The IMA megafunction groups a number of physical links to form a logical link whose bandwidth is approximately the sum of the individual link's bandwidth.
Modelware's IMA megafunction implements, in modular VHDL, the IMA Transmission Convergence sub-layer as defined by the ATM Forum. The megafunction is modular and scalable to a maximum of 32 links/16 groups. Each link can be assigned to any group or configured as pass through.
The IMA megafunction interfaces to the PHY and the ATM Layer over two UTOPIA level 2 interfaces. You can use Modelware's Multi-Channel Transmission Convergence megafunction if needed to implement the Interface-Specific Transmission Convergence sub-layer defined by the ATM Forum.
Device Utilization Example
Table 1 lists the typical device utilization results for the megafunction.
| Table 1. Typical Device Utilization for the Megafunction (1) |
| Device |
Speed Grade |
Utilization |
Performance
(fMAX) |
Parameter Setting |
| Logic Cells |
EABs (2) |
| EP20K600E |
-1 |
17,617 (3) |
204,672 (3) |
28 MHz |
32 links/16 groups |
Notes:
- Reflects full 16 link/32 group configuration.
- EABs = Embedded array blocks.
- These values are approximate.
Contact Information
For additional information, contact Modelware:
Modelware (USA)
10 West Bergen Place
Suite 105
Red Bank, NJ 07701
Tel. (732) 936-1808
Fax (732) 936-1839
E-mail: altera@modelware.com
URL: www.modelware.com
Modelware (Europe)
Kuechel str. 14
96047 Bamberg, Germany
Tel: +49 951 299-9870
Fax: +49 951 299-9872
Email: altera@modelware.com
URL: www.modelware.com
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