13.8.1.1 Undefined Length Burst Arbitration

In order to prevent long burst lengths that can lock the access to the client for an excessive period of time, the user can trigger the re-arbitration before the end of the incremental bursts. The re-arbitration period can be selected from the following Undefined Length Burst Type (ULBT) possibilities:

• Unlimited: no predetermined end of burst is generated. This value enables 1 Kbyte burst lengths.
• 1-beat bursts: predetermined end of burst is generated at each single transfer during the INCR transfer.
• 4-beat bursts: predetermined end of burst is generated at the end of each 4-beat boundary during INCR transfer.
• 8-beat bursts: predetermined end of burst is generated at the end of each 8-beat boundary during INCR transfer.
• 16-beat bursts: predetermined end of burst is generated at the end of each 16-beat boundary during INCR transfer.
• 32-beat bursts: predetermined end of burst is generated at the end of each 32-beat boundary during INCR transfer.
• 64-beat bursts: predetermined end of burst is generated at the end of each 64-beat boundary during INCR transfer.
• 128-beat bursts: predetermined end of burst is generated at the end of each 128-beat boundary during INCR transfer.

Undefined-length bursts lower than 8 beats should not be used since this may decrease the overall bus bandwidth due to arbitration and client latencies at each first access of a burst.

However, if the length of undefined-length bursts is known for a host, it is recommended to configure MATRIX_MCFG.ULBT accordingly.