SAR Controllers Have Integrated ABR Function

Targeting 155-Mbps asynchronous transfer mode (ATM) networks, IDT77252 and IDT77222 full-function segmentation and reassembly (SAR) controllers with integrated available bit rate (ABR) function come in 3.3V and 5V versions. The devices support the PCI 2.1 specs and are designed to support the PC'98 specs providing plug-and-play solutions for Windows-based networking applications. The ABR lets users obtain maximum use of network bandwidth, and firm's implementation enables bandwidth optimization per each virtual circuit, compared to the industry standard which optimizes bandwidth per chip. This lets users specify the shaping required on a per virtual circuit basis to allow tailoring of the ABR response to the individual characteristics of the user network and connection requirements. IDT77252 allows up to 16K open-transmit and receive connections, and IDT77222 supports 256 connections to reduce local memory requirements.