Texas Instruments SimpleLink CC2620 Technical Reference Manual page 1044

Functional Description
Table 12-4 describes an individual control-structure entry in the control table. Each entry is aligned on a
16-byte boundary. The entry contains four long words: the source end pointer, the destination end pointer,
the control word, and an unused entry. The inclusive end pointers point to the ending address of the
transfer. If the source or destination is nonincrementing (as for a peripheral register), then the pointer must
point to the transfer address.
The control word contains the following fields:
• Source and destination data sizes
• Source and destination address increment size
• Number of transfers before bus arbitration
• Total number of items to transfer
• Useburst flag
• Transfer mode
The control parameters for a channel can be set using the driver library function void
uDMAChannelControlSet(); function. The μDMA controller updates the transfer size and transfer mode
fields as the transfer is performed. At the end of a transfer, the transfer size indicates 0, and the transfer
mode indicates stopped. Because the control word is modified by the μDMA controller, it must be
reconfigured before each new transfer. The source and destination end pointers are not modified, so they
can be left unchanged if the source or destination addresses remain the same.
Before starting a transfer, a μDMA channel must be enabled by setting the appropriate bit in the
UDMA:SETCHANNELEN register. A channel can be disabled by setting the channel bit in the
UDMA:CLEARCHANNELEN register. At the end of a complete μDMA transfer, the controller automatically
disables the channel.
1044
Micro Direct Memory Access (µDMA)
Table 12-4. Channel Control Structure
Offset
0x000
0x004
0x008
0x00C
Copyright © 2015, Texas Instruments Incorporated
Description
Source end pointer
Destination end pointer
Control word
Unused entry
SWCU117C – February 2015 – Revised September 2015
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