Infineon PEF20550HV21: The Core of Early DSL Access Multiplexing

The Infineon PEF20550HV21 stands as a significant integrated circuit (IC) in the history of telecommunications, specifically engineered to function as a Digital Subscriber Line Access Multiplexer (DSLAM) on a single chip. This device was pivotal in the widespread adoption of DSL technology, enabling service providers to deliver high-speed internet access over existing copper telephone lines.

At its core, the PEF20550HV21 is a highly integrated controller for asymmetric digital subscriber line (ADSL) and high-bit-rate digital subscriber line (HDSL) systems. Its primary function is to aggregate data traffic from multiple subscriber lines, combining them into a single, high-speed backbone link for transmission into the wider network. This multiplexing process is the fundamental operation of a DSLAM cabinet, often located in a neighborhood's street cabinet or telephone exchange.

The IC incorporates a sophisticated Direct Memory Access (DMA) controller and an integrated High-Level Data Link Control (HDLC) engine. These features are critical for efficient data handling, allowing for the high-speed transfer of data packets between the subscriber lines and the network interface with minimal CPU intervention. This architecture ensures low latency and high throughput, which are essential for maintaining the quality of service for end-users.

Furthermore, the PEF20550HV21 was designed for robust and reliable operation in the demanding environment of telecommunications infrastructure. Its design supports various operation modes and configurability, allowing network equipment manufacturers to tailor its functionality for specific network architectures and service offerings. By integrating multiple discrete components into a single package, Infineon provided a solution that reduced the complexity, physical size, and power consumption of DSLAM line cards, contributing to more cost-effective and scalable network deployments.

ICGOODFIND Summary:

The Infineon PEF20550HV21 is a landmark DSLAM controller IC that consolidated critical multiplexing, data link control, and DMA functions into a single chip. It was instrumental in the roll-out of early high-speed internet by providing a highly integrated, reliable, and efficient solution for network infrastructure equipment, reducing costs and complexity for telecom operators.

Keywords:

DSLAM, ADSL, Multiplexer, HDLC, Infineon