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Field BUSTURN writer - Bus turnaround phase duration These bits are written by software to add a delay at the end of a write-to-read or read-to write transaction. The programmed bus turnaround delay is inserted between an asynchronous read (in muxed or mode D) or write transaction and any other asynchronous /synchronous read/write from/to a static bank. If a read operation is performed, the bank can be the same or a different one, whereas it must be different in case of write operation to the bank, except in muxed mode or mode D. In some cases, whatever the programmed BUSTRUN values, the bus turnaround delay is fixed as follows: The bus turnaround delay is not inserted between two consecutive asynchronous write transfers to the same static memory bank except in muxed mode and mode D. There is a bus turnaround delay of 1 FMC clock cycle between: Two consecutive asynchronous read transfers to the same static memory bank except for modes muxed and D. An asynchronous read to an asynchronous or synchronous write to any static bank or dynamic bank except in modes muxed and D mode. There is a bus turnaround delay of 2 FMC clock cycle between: Two consecutive synchronous write operations (in Burst or Single mode) to the same bank. A synchronous write (burst or single) access and an asynchronous write or read transfer to or from static memory bank (the bank can be the same or a different one in case of a read operation. Two consecutive synchronous read operations (in Burst or Single mode) followed by any synchronous/asynchronous read or write from/to another static memory bank. There is a bus turnaround delay of 3 FMC clock cycle between: Two consecutive synchronous write operations (in Burst or Single mode) to different static banks. A synchronous write access (in Burst or Single mode) and a synchronous read from the same or a different bank. The bus turnaround delay allows to match the minimum time between consecutive transactions (tEHEL from NEx high to NEx low) and the maximum time required by the memory to free the data bus after a read access (tEHQZ): (BUSTRUN + 1) KCK_FMC period ≥ tEHELmin and (BUSTRUN + 2)KCK_FMC period ≥ tEHQZmax if EXTMOD = 0 (BUSTRUN + 2)KCK_FMC period ≥ max (tEHELmin, tEHQZmax) if EXTMOD = 1. …