FOLDED ARCHITECTURE OF SCHEDULER FOR AREA OPTIMIZATION IN AN ON-CHIP SWITCH FABRIC

As the feature sizes of the manufacturing processes is constantly shrinking, the possibility and demand for more functionality on a single chip goes up. This can lead to many problems,e.g. as the memory access bandwidth through the bus gets too low to cope with the demand, also the electrical performance of the bus gets degraded as the number of modules are increased. Our proposed architecture makes use of a switch fabric structure to eliminate the traditional drawbacks of bus based design. Scheduler becomes the integral part of the switch which decides the scheduling of the SOC devices. In this paper, we have proposed an area efficient scheduler which saves around 22 26% of the total scheduler area on the silicon die. This becomes possible because the arbiter we designed is capable of executing two different steps of Islip algorithm in two different clock cycles. In the first cycle, it acts as a grant arbiter while the next cycle makes it an accept arbiter. The design is modified using the folding concept which is used to reduce the silicon area by time multiplexing many algorithm operations into a single functional unit. Both the design of the scheduler is synthesized using 90nm SAED library using Design Compiler of SYNOPSYS with the design constraint of input delay, output delay and clock skew. The original scheduler occupies around 22206 area unit while the proposed scheduler occupies around 17285 area unit of the total silicon area considering the constraint of input delay, output delay and clock skew. The area includes both cell area (Combinational + NCombinational) and Interconnect area.