Symphony DSP56724/DSP56725 Multi-Core Audio Processors, Rev. 0
10-14
Freescale Semiconductor
Serial Host Interface (SHI, SHI_1)
10.3.8.9
HCSR Bus-Error Interrupt Enable (HBIE)—Bit 10
The read/write control bit HBIE enables the SHI bus-error interrupt:
•
If the HBIE bit is cleared, then bus-error interrupts are disabled, and the HBER status bit must be
polled to determine if an SHI bus error occurred.
•
If both the HBIE and HBER bits are set, then the SHI requests an SHI bus-error interrupt service
from the interrupt controller. The HBIE bit is cleared by hardware and software resets.
NOTE
Clearing the HBIE bit masks a pending bus-error interrupt only after a one
instruction cycle delay. If the HBIE bit is cleared in a long interrupt service
routine, it is recommended that at least one other instruction is between the
instruction (that clears the HBIE bit) and the RTI instruction at the end of
the interrupt service routine.
10.3.8.10 HCSR Transmit-Interrupt Enable (HTIE)—Bit 11
The read/write control bit HTIE is used to enable the SHI transmit data interrupts:
•
If the HTIE bit is cleared, then the transmit interrupts are disabled, and the HTDE status bit must
be polled to determine if the HTX register is empty.
•
If both the HTIE and HTDE bits are set and the HTUE bit is cleared, then the SHI requests an SHI
transmit-data interrupt service from the interrupt controller.
•
If both the HTIE and HTUE bits are set, then the SHI requests an SHI transmit-underrun-error
interrupt service from the interrupt controller.
The HTIE bit is cleared by hardware and software resets.
NOTE
Clearing the HTIE bit masks a pending transmit interrupt only after a one
instruction cycle delay. If the HTIE bit is cleared in a long interrupt service
routine, it is recommended that at least one other instruction separates the
instruction (that clears the HTIE bit) and the RTI instruction at the end of
the interrupt service routine.
10.3.8.11 HCSR Receive Interrupt Enable (HRIE[1:0])—Bits 13–12
The read/write control bits HRIE[1:0] are used to enable the SHI receive-data interrupts:
•
If the HRIE[1:0] bits are cleared, then the receive interrupts are disabled, and the HRNE and HRFF
status bits must be polled to determine if there is data in the receive FIFO.
•
If the HRIE[1:0] bits are not cleared, then receive interrupts are generated according to
The HRIE[1:0] bits are cleared by hardware and software resets.