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CC1110 AES, DMA, and Radio communication

Hi All,

I am using the TI CC1110.  I am using the radio at 915 MHz, using DMA channel 0 to transfer data to/from the radio.  The radio works fine, and I can send and receive data at will.

I recently implemented AES using DMA channel 2 to download data to the AES coprocessor and DMA channel 3 to upload data from the AES coprocessor.  I loosely based this implementation on DN108 (having read the DN108 discussion thread).  The AES module works.  I can encrypt and decrypt data.

However, I have discovered that, after AES encrypting some data, the radio will no longer work.  Everything "runs" correctly... all interrupts, etc. work, but there is no RF transmission.

I can initialize the AES coprocessor, download a key and an IV to it using DMA, and the radio will continue working.  But, once I actually trigger an AES encryption by setting ENCCS |= ENCCS_ST (the start flag in the register), the radio will no longer work.

I first suspected that the AES module was disabling some interrupt or corrupting some DMA configuration, but this is not the case.  So, my question:  Has anyone else run into problems using AES in DMA mode and the radio in the CC1110?  Is there some undocumented workaround that I should be aware of?  (i.e. Do you have to use DMA channel 0 for AES or something similar to that???)

Thanks in advance for any replies,

-Dave Hill

 

[EDIT]

This problem has been solved.  The problem was not related to the CC1110, but rather to the tool I was using to detect the RF.  The radio actually worked just fine and transmitted its data, but the tool I was using had a bug (which has now been squashed).

[END EDIT]