
Inter-Core Communication (ICC)
Symphony DSP56724/DSP56725 Multi-Core Audio Processors, Rev. 0
Freescale Semiconductor
13-15
13.3.3
Polling
The poll register is a 24-bit R/W register for the two DSP cores to share data or software-defined status
flags to the other core. The two cores can only read their own read-only poll registers to obtain the data
from the other core. See
.
Figure 13-17. Poll Data Register
For the two DSP cores, poll register ICPR2 is read-writable, and poll register ICPR1 is read-only. One core
writes data to its ICPR2 poll register, after which the other core reads its own ICPR1 to obtain the data
(that was written to the ICPR2 register).
13.3.4
Error Interrupts
The maskable error interrupt for each core is generated when one core writes to the ICDR3 register and
the other core reads the ICDR4 register at the same time. The core that reads the ICDR4 register will
receive this error interrupt. This situation will not happen if reading the ICDR4 register is always executed
in the maskable interrupt service routine. Generating this error interrupt condition is only for handling such
an error in case that the wrong operation takes place.
For the communications via maskable interrupt, users should always read the ICDR4 register in the
maskable interrupt service routine.
shows how error interrupts are generated.
Figure 13-18. Error Interrupt Generation
When this error condition occurs, the maskable interrupt will not be generated (even it is enabled), because
the maskable interrupt flag is not set by the hardware when the error condition occurs. The ICC error
interrupt is shared with the EMC error interrupt. For distinguishing the two interrupts (ICC error and EMC
Core-0 peripheral bus
Core-1 peripheral bus
24-bit Poll Data Register
Core 0 ICPR1
Core 1 ICPR2
Core 1 ICPR1
Core 0 ICPR1
ICCR3
Error interrupt
Other Core
reads
(ICDR4)
One Core
writes
(ICDR3)
A Write and Read operation
at the same time sets the error flag
EIE
ICDR3 Register
Other Core writes
1 to clear the EF
EF