Programmable transaction initiator architecture for systems with secure and non-secure modes

摘要

A wireless device dynamically programs a control register for a command-chain driven DMA device. The control register stores a beginning address of the linked list of commands and a secure bit. The secure bit is set if the transaction writing register is secure and a bit in the data being written into the register is set. DMA devices and other bus-mastering peripherals perform tasks described via a command chain that has access to secure resources when the processor is operating in the secure mode and the secure bit is set.