
Inter-processor communication controller (IPCC)
RM0453
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RM0453 Rev 2
Figure 39. IPCC Simplex - Receive procedure state diagram
To receive a communication, the channel occupied interrupt is unmasked (CHnOM = 0):
•
On a RX occupied interrupt, the receiving processor checks which channel became
occupied, masks the associated channel occupied interrupt (CHnOM) and reads the
communication data from memory.
•
Once the complete communication data is retrieved, the channel status is cleared to
free with CHnC. This gives memory access back to the sending processor and may
generate the TX free interrupt.
•
Once the channel status is cleared, the channel occupied interrupt is unmasked
(CHnOM = 0).
9.3.3
IPCC Half-duplex channel mode
The Half-duplex channel mode is used when one processor sends a communication and the
other processor sends a response to each communication (ping-pong).
In Half-duplex channel mode, a single dedicated memory location is assigned to
communication data and response, and is used to transfer data in both directions. The
sending processor channel status flag CHnF is assigned to the channel and used by both
processors (see
Once the processor A posted the communication data into memory, it sets the processor A
channel status flag CHnF to occupied with CHnS (giving memory access to processor B).
Once the processor B retrieved the communication data from memory, it does not change
the channel status flags. The memory access is kept by processor B for the response.
Once the processor B posted the response into memory, it clears the channel status flag
CHnF to free with CHnC (giving memory access back to processor A).
MS42432V1
MASK
Channel N
occupied interrupt
Read
Communication
data from Memory
Set Channel N free
UNMASK
Channel N
occupied interrupt
End
Write CHnOM = 0
Write CHnOM = 1
RX
occupied interrupt
RX
occupied interrupt
Read CHnF = 1
Complete communication retrieved
Write CHnC (set CHnF = 0)