µDMA Channel Control Structure
1210
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Micro Direct Memory Access ( µDMA)
Table 16-16. DMA Channel Control Word (DMACHCTL) Register Field Descriptions (continued)
Bit
Field
Value
Description
29-28
DSTSIZE
Destination Data Size
This field configures the destination item data size.
Note:
DSTSIZE must be the same as SRCSIZE.
0x0
Byte
8-bit data size
0x1
Half-word
16-bit data size
0x2
Word
32-bit data size
0x3
Reserved
27-26
SRCINC
Source Address Increment
This field configures the source address increment.
The address increment value must be equal or greater than the value of the source size
(SRCSIZE).
0x0
Byte
Increment by 8-bit locations
0x1
Half-word
Increment by 16-bit locations
0x2
Word
Increment by 32-bit locations
0x3
No increment
Address remains set to the value of the Source Address End Pointer (DMASRCENDP) for the
channel
25-24
SRCSIZE
Source Data Size
This field configures the source item data size.
Note:
DSTSIZE must be the same as SRCSIZE.
0x0
Byte
8-bit data size.
0x1
Half-word
16-bit data size.
0x2
Word
32-bit data size.
0x3
Reserved
23-18
Reserved
Reserved
17-14
ARBSIZE
Arbitration Size
This field configures the number of transfers that can occur before the µDMA controller re-
arbitrates. The possible arbitration rate configurations represent powers of 2 and are shown below.
0x0
1 Transfer
Arbitrates after each
μ
DMA transfer
0x1
2 Transfers
0x2
4 Transfers
0x3
8 Transfers
0x4
16 Transfers
0x5
32 Transfers
0x6
64 Transfers
0x7
128 Transfers
0x8
256 Transfers
0x9
512 Transfers
0xA-
0xF
1024 Transfers
In this configuration, no arbitration occurs during the
μ
DMA transfer because the maximum transfer
size is 1024.