The IPC allows communication between the two CPU subsystems (i.e. CPU1 and CPU2).
- Message RAMs
- IPC flags and interrupts
- IPC command registers
- Flash pump semaphore
- Clock configuration semaphore
- Free-running counter
There are up to 16 blocks of shared RAM on F2837xD devices. These shared RAM blocks are typically used by the application, but can also be used for transferring messages and data. Each block can individually be owned by either CPU1 or CPU2.
CPU1 core ownership:
At reset, CPU1 owns all of the shared RAM blocks. In this configuration CPU1 core can freely use the memory blocks. CPU1 can read, write or execute from the block and CPU1.DMA can read or write. On the CPU2 core, CPU2 and CPU2.DMA can only read from these blocks. Blocks owned by the CPU1 core can be used by the CPU1 to send CPU2 messages. This is referred to as C1toC2.
CPU2 core ownership:
After reset, the CPU1 application can assign ownership of blocks to the CPU2 subsystem. In this configuration, CPU2 core can freely use the blocks. CPU2 can read, write or execute from the block and the CPU2.DMA can read or write. CPU1 core, however can only read from the block. Blocks owned by CPU2 core can be used can be used to send messages from the CPU2 to CPU1. This is referred to as C2toC1.
The F2837xD has two dedicated message RAM blocks. Each block is 1K words in length. Unlike the shared RAM blocks, these blocks provide communication in one direction only and cannot be reconfigured.
CPU1 to CPU2 C1toC2 message RAM:
The first message RAM is the CPU1 to CPU2 or C1toC2. This block can be read or written to by the CPU1 and read by the CPU2. CPU1 can write a message to this block and then the CPU2 can read it.
CPU2 to CPU1 C2toC1 message RAM:
The second message RAM is the CPU2 to CPU1 or C2toC1. This block can be read or written to by CPU2 and read by CPU1. This means CPU2 can write a message to this block and then CPU1 can read it. After the sending CPU writes a message it can inform the receiver CPU that it is available through an interrupt or flag.
