14.6.4 Message Memory Configuration

The message objects of the TEF, TXQ and transmit/receive FIFOs are located in RAM (see Figure 14-14). The application must configure the number of message objects in a FIFO between Message Object 0 and Message Object 31. Additionally, the application must configure the payload size of the message objects in each FIFO. This configuration determines where message objects are located in RAM. The RAM allocation can only be configured in Configuration mode. The start of the Message Memory is defined by CxFIFOBA register, which is word aligned.

In order to optimize RAM usage, the application should start configuring the RAM with the TEF, followed by the TXQ and continue with FIFO 1, FIFO 2, FIFO 3 and so on. In case a user application requires TEF, TXQ and 16 additional FIFOs, it should configure TEF and TXQ, followed by FIFO 1 through FIFO 16. It is not necessary to configure the unused FIFOs 17 through 31.