There may be a latency between the assertion of the read/write controlling signal and the assertion of the NWAIT signal by the device. The programmed pulse length of the read/write controlling signal must be at least equal to this latency plus the 2 cycles of resynchronization + one cycle. Otherwise, the SMC may enter the hold state of the access without detecting the NWAIT signal assertion. This is true in Frozen mode as well as in Ready mode. This is illustrated in the following figure.
When SMC_MODE.EXNW_MODE is enabled (ready or frozen), the user must program a pulse length of the read and write controlling signal of at least:
Minimal pulse length = NWAIT latency + 2 resynchronization cycles + 1 cycle
