LM3S5R36_13 Datasheet, PDF (377/1063 Pages) Texas Instruments – LM3S5R36 Microcontroller

NRND: Not recommended for new designs.
Stellaris^® LM3S5R36 Microcontroller
Bit/Field
17:14
13:4
3
Name
ARBSIZE
XFERSIZE
NXTUSEBURST
Type
R/W
R/W
R/W
Reset
-
Description
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.
Value Description
0x0
1 Transfer
Arbitrates after each μDMA 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 μDMA
transfer because the maximum transfer size is 1024.
-
Transfer Size (minus 1)
This field configures the total number of items to transfer. The value of
this field is 1 less than the number to transfer (value 0 means transfer
1 item). The maximum value for this 10-bit field is 1023 which represents
a transfer size of 1024 items.
The transfer size is the number of items, not the number of bytes. If the
data size is 32 bits, then this value is the number of 32-bit words to
transfer.
The μDMA controller updates this field immediately prior to entering the
arbitration process, so it contains the number of outstanding items that
is necessary to complete the μDMA cycle.
-
Next Useburst
This field controls whether the Useburst SET[n] bit is automatically set
for the last transfer of a peripheral scatter-gather operation. Normally,
for the last transfer, if the number of remaining items to transfer is less
than the arbitration size, the μDMA controller uses single transfers to
complete the transaction. If this bit is set, then the controller uses a burst
transfer to complete the last transfer.
October 06, 2012
377
Texas Instruments-Production Data