The optimal use of bandwidth
requires that TX local bus data can be written at a rate faster
than it can be delivered on the serial interface. This means that
there must be backpressure, or flow-control, on the TX segmented
LBUS. The signals used to implement backpressure are tx_rdyout and tx_ovfout . These signals are common for all
segments. When responding to backpressure during a clock cycle,
none of the tx_enainS can be active.