Esai Interrupt Requests - Motorola DSP56367 User Manual

Note: If the ESAI receiver section is already operating with some of the receivers,
enabling additional receivers on the fly (i.e. without first putting the ESAI receiver
in the personal reset state) by setting their REx control bits will result in erroneous
data being received as the first data word for the newly enabled receivers.
10.4.3

ESAI INTERRUPT REQUESTS

The ESAI can generate eight different interrupt requests (ordered from the highest to the
lowest priority):
1. ESAI Receive Data with Exception Status.
Occurs when the receive exception interrupt is enabled (REIE=1 in the RCR register),
at least one of the enabled receive data registers is full (RDF=1), and a receiver
overrun error has occurred (ROE=1 in the SAISR register). ROE is cleared by first
reading the SAISR and then reading all the enabled receive data registers.
2. ESAI Receive Even Data
Occurs when the receive even slot data interrupt is enabled (REDIE=1), at least one of
the enabled receive data registers is full (RDF=1), the data is from an even slot
(REDF=1), and no exception has occurred (ROE=0 or REIE=0).
Reading all enabled receiver data registers clears RDF and REDF.
3. ESAI Receive Data
Occurs when the receive interrupt is enabled (RIE=1), at least one of the enabled
receive data registers is full (RDF=1), no exception has occurred (ROE=0 or REIE=0),
and no even slot interrupt has occurred (REDF=0 or REDIE=0).
Reading all enabled receiver data registers clears RDF.
4. ESAI Receive Last Slot Interrupt
Occurs, if enabled (RLIE=1), after the last slot of the frame ended (in network mode
only) regardless of the receive mask register setting. The receive last slot interrupt may
be used for resetting the receive mask slot register, reconfiguring the DMA channels
and reassigning data memory pointers. Using the receive last slot interrupt guarantees
that the previous frame was serviced with the previous setting and the new frame is
serviced with the new setting without synchronization problems. Note that the
maximum receive last slot interrupt service time should not exceed N-1 ESAI bits
service time (where N is the number of bits in a slot).
5. ESAI Transmit Data with Exception Status
Occurs when the transmit exception interrupt is enabled (TEIE=1), at least one
transmit data register of the enabled transmitters is empty (TDE=1), and a transmitter
underrun error has occurred (TUE=1). TUE is cleared by first reading the SAISR and
then writing to all the enabled transmit data registers, or to the TSR register.
MOTOROLA
Enhanced Serial Audio Interface (ESAI)
DSP56367
Operating Modes
10-49