Microelectronics, Computers and Communications

This talk describes a VLSI device - Synchronous Protocol Data Formatter with time-multiplexed serial interface (SPYDER-T) to implement the ISDN primary rate interface. The SPYDER-T performs all the low level formatting functions and provide an interface through which a host can handle higher level functions including flow control. The SPYDER-T reads the data from the shared memory, performs the low level formatting functions using bit synchronous HDLC/SDLC protocols, and transmits it to the serial concentration highway in a time multiplexed manner up to 32 channels. Similarly, the SPYDER-T receives the serial data from the concentration highway and stores the data in the shared memory, linked by frame, on a channel by channel basis.