The clocked circuit in Figure P12.20 is an arbiter. Suppose two devices, 1 and 2, can request a resource such as a bus at any instant. The problem is to ensure that only one requester is granted the resource - even if both requests are made simultaneously. The circuit of device 2 has two request inputs plus a clock and two grant outputs. Explain how the circuit is able to perform its function reliably. The circuit uses edge-triggered flip-flops and that it is immune to metastablilty.

Transcribed Image Text:

FIGURE P12.20 Request1 Clock Request2 A CLK B D CLK CLK Latch 1a. CLK Latch 2a AA BB D CLK D CLK Pre CLK Latch 1b Pre CLK Latch 2b Q Q Grant1 Grant2 Cengage Leaming 2014