PM73487

The QRT switch fabric interface of PM73487 consists of four groups of signals from both the ingress (receive ide) and the egress (transmit side). Each group consists of a Start-Of-Cell (SE_SOC_OUT) signal,  nibble-wide data bus, and a backpressure acknowledgment (BP_ACK_IN) signal. The tart-Of-Cell (SE_SOC_OUT) signal is transmitted at the ingress at the same time as the beginning f a cell. SE_SOC_OUT PM73487 on the ingress is common to all four groups. The BP_ACK_OUT PM73487 ignal flows from the egress through the switch fabric, in the direction opposite the data, and indicates hether a cell has successfully passed through the switch fabric. Other signals associated PM73487 the switch fabric interface are the switch element clock (SE_CLK) and RX_CELL_START. o support the highest possible throughput for various switch fabric configurations, a clock peed-up factor of 1.6 is used. That is, the switch fabric is run at a rate that is effectively 1.6 times aster than the line rate.