The MATRIX provides some speculative bus granting techniques in order to anticipate access requests from masters. This technique reduces latency at the first access of a burst, or for a single transfer, as long as the slave is free from any other master access. Bus granting sets a different default master for every slave.
At the end of the current access, if no other request is pending, the slave remains connected to its associated default master. A slave can be associated with three kinds of default masters:
To change from one type of default master to another, the MATRIX user interface provides the Slave Configuration registers, one for every slave, that set a default master for each slave. The Slave Configuration register contains the fields DEFMSTR_TYPE and FIXED_DEFMSTR. The 2-bit DEFMSTR_TYPE field selects the default master type (no default, last access master, fixed default master), whereas the 4-bit FIXED_DEFMSTR field selects a fixed default master provided that DEFMSTR_TYPE is set to fixed default master. Please refer to the "Bus Matrix Slave Configuration Registers" section.