[FAQ] F29x RTDMA: Frequently Asked Questions

For reference, please see F29x General FAQ for other IP/peripherals

F29x RTDMA Frequently Asked Questions

Even though RTDMA1 and RTDMA2 are performing the same configuration process by default, why is an NMI interrupt is generated when RTDMA2 is executed?

• At power up, certain modules such as CPU1 and CPU2, CPU1 PIPE and CPU2 PIPE, and RTDMA1 and RTDMA2 operate in lockstep mode. In order to specifically configure RTDMA2, you must use configure the device to be in Split-Lock (modules operating independently. This can be done in the first selection in the SysConfig SYSCTL module. At this point, RTDMA1 and RTDMA2 operate independently of each other. Another helpful feature is to use the various scripts provided to check for cause / location of errors, interrupts, etc. Refer to "No.145 TI" for more information. Please refer to sections 5.1.3 and 14.10 in the TRM.

Can I use RTDMA2 while in lockstep mode? How can we use RTDMA2 normally?

• On F29x, our lock step or split lock control bit is governed by the LSEN bit. You cannot enable RTDMA2 while in lock step mode. In order to use 14 DMA channels you’ll have to disable lock step. The lock step feature we have on our F29x governs all the peripheral’s functionality and doesn’t provide you the granularity to enable or disable lockstep per peripheral.