
RM0453 Rev 2
381/1454
RM0453
Inter-processor communication controller (IPCC)
391
Figure 38. IPCC Simplex - Send procedure state diagram
To send communication data:
•
The sending processor checks the channel status flag CHnF:
–
When CHnF = 0, the channel is free (last communication data retrieved by
receiving processor) and the new communication data can be written.
–
When CHnF = 1, the channel is occupied (last communication data not retrieved
by receiving processor) and the sending processor unmasks the channel free
interrupt (CHnFM = 0).
–
On a TX free interrupt, the sending processor checks which channel became free
and masks the channel free interrupt (CHnFM = 1). Then the new communication
can take place.
•
Once the complete communication data is posted, the channel status is set to occupied
with CHnS. This gives memory access to the receiving processor and generates the
RX occupied interrupt.
TX
free interrupt
MS42431V2
UNMASK
Channel N
free interrupt
Wait for
TX free interrupt
TX free interrupt
MASK
Channel N
free interrupt
Write
Communication
data to memory
Set Channel N
occupied
End
CHnF = 1
Write CHnFM = 1
Send
Communication data
CHnF = 0
Read CHnF
Complete communication posted
Write CHnS (set CHnF = 1)
Write CHnFM = 0
Read CHnF = 0