4.3.3 Buffer Queue Support

As in MPLAB Harmony v2 drivers, MPLAB Harmony v3 drivers also allow buffer queuing. The driver can queue up a client’s new request while it is already processing an earlier request. In MPLAB Harmony v3, queuing support is available only for Asynchronous mode of the drivers. Synchronous drivers are blocking in nature, therefore the queuing feature is not applicable (Synchronous and Asynchronous drivers in MPLAB Harmony v3 is discussed in a following section).

In MPLAB Harmony v3, to configure the buffer queue size, first configure the driver in Asynchronous mode through driver’s common configurations as shown in Driver's Common Configuration and then the Transfer Queue Size is configured through a peripheral-specific driver instance configuration as shown in the following figure: