High Performance DMA Controller
UG0331 User Guide Revision 15.0
254
8.4.1.11 Descriptor 1 Control Register
Table 160 •
HPDMAD1CR_REG
Bit
Number Name
Reset
Value
Description
15:0
HPDMACR_DCP1_XFR_SIZE
0
Descriptor 1 transfer size in bytes.
Defines number of bytes to be transferred in a descriptor 1
transfer.
All zeroes in this field indicates 64-KB transfers.
As all the transfers are word aligned, the 2 LSBs 1:0 are
ignored.
16
HPDMACR_DCP_VALID[1]
0
1: Indicates the descriptor 1 is valid and ready to transfer.
On completing a descriptor 1 transfer, the HPDMA controller
clears this bit.
Once the descriptor valid bit is set, descriptor fields such as
Source Address, Destination Address, Transfer Size, and
Descriptor Valid bits cannot be overwritten.
When this bit is set, HPDMA clears the status of the previous
transfer, which includes transfer complete, transfer error
interrupts, and corresponding descriptor 1 Status register.
17
HPDMACR_XFR_DIR[1]
0
Descriptor 2 data transfer direction:
0: AHB bus matrix to MSS DDR bridge
1: MSS DDR bridge to AHB bus matrix
18
HPDMACR_DCP_CLR[1]
0
When this bit is set, HPDMA clears the descriptor 1 fields.
HPDMA terminates the current transfer and resets descriptor
status and control registers.
This bit is always read back as zero.
19
HPDMACR_DCP_PAUSE[1]
0
1: HPDMA pauses Descriptor 1 transfers, does idle transfers.
0: HPDMA resumes descriptor 1 transfers from where they
have stopped.
20
HPDMACR_XFR_CMP_INT[1]
0
1: HPDMA asserts interrupt on completion of descriptor 1
transfers without error.
0: HPDMA will not generate transfer complete interrupt.
21
HPDMACR_XFR_ERR_INT[1]
0
1: HPDMA asserts transfer error interrupt on error during
descriptor 1 transfers.
0: HPDMA will not generate transfer error interrupt.
22
HPDMACR_NON_WORD_INT[1] 0
Non-word interrupt enable
1: HPDMA asserts transfer error interrupt when non-word
aligned transfer size is programmed in
HPDMACR_DCP1_XFR_SIZE and HPDMA continues the
same descriptor transfer.
0: HPDMA will not generate interrupt.
31:23
Reserved
0
Software should not rely on the value of a reserved bit. To
provide compatibility with future products, the value of a
reserved bit should be preserved across a read-modify-write
operation.