Interrupt Service Routine (ISR) Flowcharts
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USB Function Module
13.6.4 Endpoint 0 RX Interrupt Handler
The endpoint 0 RX portion of the general USB interrupt handler, shown in
Figure 13–17, must handle general USB interrupts related to control OUT
transactions on endpoint 0. Notice that no EP0 interrupt is generated for
autodecoded control transfers.
13.6.5 Endpoint 0 TX Interrupt Handler
The endpoint 0 TX portion of the general USB interrupt handler, shown
in Figure 13–19, must handle general USB interrupts related to control IN
transactions on endpoint 0.
The endpoint 0 TX interrupt handler must be able to move data into the end-
point 0 TX FIFO when the application buffer for endpoint 0 TX data is not empty
and an endpoint 0 TX interrupt occurs signaling an ACKed non-autodecoded
endpoint 0 IN transaction. This data can be control read data stage information
or control write status stage handshaking information.