ARM Technical Support Knowledge Articles

Section 2.2. Protection Information

Applies to: PL08x DMAC (DM & SM)

Answer

Applies to: PL08x DMAC

Protection information is put in Prot bits in the DMACCx Control Register. Is this information used both for source and destination transactions for a particular channel?

HPROT[3:0] bits are programmed by software for each PrimeCell Peripheral DMA channel and the protection information is indeed placed in the DMACCx Control Register and consists of three bits. Now AHB protection (and access) information is provided to the source and destination peripherals when a transfer occurs. This transfer information is provided by programming the DMA channel (the Prot bit in the DMACCx control register). These bits are programmed by software and can be used by the peripheral as necessary. The three bits of information provided being:

  • user/privileged;
  • cacheable/non-cacheable and
  • bufferable/non-bufferable.

Article last edited on: 2008-09-09 15:47:25

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