An TM switching system should be capable of handling multimedia traffic, which has different bit-rates and diversiied quality requirements. A self-routing switch is a key piece of equipment for attaining this goal. This paper proposes. a new switch construction and describes its LSI design and fabrication.The proposed switch, which is a memory switch with dynamic link speed control, can dynamically change link speeds according to traffic flow, thereby achieving high performance in any imbalanced traffic condition. The switch element also functions as a multiplexer/demultiplexer and an inserter/dropper. Thus, the proposed LSI is expected to be a key component in ATM-based equipment.A 4x4 memory switch LSI using 0.8-pm BiCMOS technology is developed, and a switching network with a capacity of 256 155-Mb/s lines is tested. Results show that the proposed LSI makes possible a compact, economical ATM switching system.