AN666 SILABS [Silicon Laboratories], AN666 Datasheet - Page 7

• Manufacturer Part Number: AN666
• Description: USAGE GUIDE FOR SIM3U1XX, SIM3C1XX, AND SIM3L1XX DMA AND DTM MODULES
• Manufacturer: SILABS [Silicon Laboratories]

17:14
13:4
2:0
Bit
3
RPOWER
NCOUNT
Reserved
Name
TMD
Transfer Size Select.
This field determines the number of data transfers between each DMA channel re-arbi-
tration. The number of data transfers is given by:
This field is ignored for peripherals that support single data requests only. A value of 0
for RPOWER should be used for channels interfacing with these types of peripherals.
Transfer Total.
This field is the total number of transfers for the DMA channel. The total number is
NCOUNT + 1, so software requiring a total of 4 transfers would set the NCOUNT field
to 3.
The DMA controller decrements this field as transfers are made.
Must write 0 to this bit.
Transfer Mode.
000: Stop the DMA channel.
001: Use the Basic transfer type (single descriptor only).
010: Use the Auto-Request transfer type (single descriptor only).
011: Use the Ping-Pong transfer type (primary and alternate descriptors).
100: Use the Memory Scatter-Gather Primary transfer type (primary, alternate, and
scattered descriptors).
101: Use the Memory Scatter-Gather Alternate transfer type (primary, alternate, and
scattered descriptors).
110: Use the Peripheral Scatter-Gather Primary transfer type (primary, alternate, and
scattered descriptors).
111: Use the Peripheral Scatter-Gather Alternate transfer type (primary, alternate, and
scattered descriptors).
Number of Transfers
Rev. 0.1
=
2
RPOWER
Function
AN666
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