DMA Channel Thread in Secure State
When the
CNS
bit is 0, the DMA channel thread is programmed to operate in the Secure state and it only
performs secure instruction fetches.
When a DMA channel thread in the Secure state processes the following instructions:
•
DMAWFE
—The DMAC halts execution of the thread until the event occurs. When the event occurs, the
DMAC continues execution of the thread, irrespective of the security state of the corresponding
INS
bit,
in the
CR3
register.
•
DMASEV
—The DMAC creates the event interrupt, irrespective of the security state of the corresponding
INS
bit, in the
CR3
register.
•
DMAWFP
—The DMAC halts execution of the thread until the peripheral signals a DMA request. When
this occurs, the DMAC continues execution of the thread, irrespective of the security state of the
corresponding
PNS
bit, in the
CR4
register.
•
DMALDP
and
DMASTP
—The DMAC sends a message to the peripheral to communicate that data transfer
is complete, irrespective of the security state of the corresponding
PNS
bit, in the
CR4
register.
•
DMAFLUSHP
—The DMAC clears the state of the peripheral and sends a message to the peripheral to
resend its level status, irrespective of the security state of the corresponding
PNS
bit, in the
CR4
register.
When a DMA channel thread is in the Secure state, it enables the DMAC to perform secure and non-secure
AXI accesses.
DMA Channel Thread in Non-Secure State
When the
CNS
bit is 1, the DMA channel thread is programmed to operate in the Non-secure state and it
only performs non-secure instruction fetches.
DMA Controller
Altera Corporation
cv_54016
DMA Channel Thread in Secure State
16-20
2013.12.30