IIR Accelerator
6-64 ADSP-214xx SHARC Processor Hardware Reference
Accelerator input and output channels are used to connect to internal 
memory. 
Note that the IIRCTL2 register is part of the IIR TCB. This allows 
to program individual IIR channels having different control 
attributes.
Interrupts
The IIR accelerator has two interrupts that are programmable through the 
PICR registers ( Appendix B, Peripheral Interrupt Control). The ACC0I and 
ACC1I source bits are used to connect IIR interrupts to the peripheral 
interrupt inputs of the core. 
One interrupt line is shared by all the DMA interrupts and the other by 
MAC status interrupts. Separate status registers are provided to further 
differentiate the various sources.
Interrupt Sources
There are two interrupt sources associated with the accelerator. The 
IIR_CCINTR bit in the IIRCTL1 register controls these interrupts. When set, 
the bit generates window complete interrupt and when cleared (default), 
an interrupt is generated after all the channels are complete.
Window Complete Interrupt – This interrupt is generated at the end of 
each channel when all the output samples are calculated corresponding to 
a window and updated index values are written back.
Table 6-4. Overview of IIR Interrupts
Interrupt Source Interrupt Condition Interrupt 
Completion
Interrupt 
Acknowledge
Default IVT
IIR (2 channels) - Window Complete 
- Channel Complete
- MAC status
- Internal trans-
fer completion
RTI instruction Need to route  
ACCxI (PICRx) 
to any PxxI