39.7.13.3 Ready Mode

In Ready mode (EXNW MODE = 11), the EBI behaves differently. Normally, the EBI begins the access by down counting the setup and pulse counters of the read/write controlling signal. In the last cycle of the pulse phase, the resynchronized NWAIT signal is examined.

If asserted, the EBI suspends the access. After deassertion, the access is completed and the hold step of the access is performed.

This mode must be selected when the external device uses deassertion of the NWAIT signal to indicate its ability to complete the read or write operation.

If the NWAIT signal is deasserted before the end of the pulse, or asserted after the end of the pulse of the controlling read/write signal, it will have impact on the access length.