One-Wire Master Registers
1520
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
1-Wire Master Module
22.5.9 ONEWIREDMA Register (Offset = 0x120) [reset = 0x0]
1-Wire uDMA Control (ONEWIREDMA), offset 0x120
The 1-Wire DMA Control (ONEWIREDMA) register is used to configure the uDMA operation for 1-Wire.
This mechanism supports both uDMA write operations, uDMA read operations, small write/read
operations, and scatter-gather support of mixed operations.
NOTE:
This register is cleared when the dma_done signal to the 1-Wire module is asserted by the
uDMA and the DMA bit in the ONEWIRERIS register is set.
ONEWIREDMA is shown in
and described in
.
Return to
Figure 22-15. ONEWIREDMA Register
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RESERVED
R-0x0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESERVED
SG
DMAOP
RST
R-0x0
R/W-
0x0
R/W-0x0
R/W-
0x0
Table 22-13. ONEWIREDMA Register Field Descriptions
Bit
Field
Type
Reset
Description
31-4
RESERVED
R
0x0
3
SG
R/W
0x0
Scatter-Gather Enable. This bit should be enabled when DMAOP =
0x1 and the scatter-gather method is being used. This bit self clears
after it has performed the µDMA request.
0x0 = No effect
0x1 = µDMA is requested at start of operation and all requests after
are on completion of transactions.
2-1
DMAOP
R/W
0x0
µDMA Operation. The programmed operation starts when reset
completes if the RST bit in the ONEWIRECS register is set. If RST is
not set, then write requests the µDMA immediately and read starts
on a write to the ONEWIREDATW register.
0x0 = µDMA disabled
0x1 = µDMA single read: 1-Wire requests µDMA to read
ONEWIREDATR register after each read transaction.
0x2 = µDMA multiple write: 1-Wire requests µDMA to load whenever
the ONEWIREDATW register is empty.
0x3 = µDMA multiple read: An initial read occurs and subsequent
reads start after µDMA has read the ONEWIREDATR register.
0
RST
R/W
0x0
µDMA Reset.
0x0 = No effect.
0x1 = A reset is issued and no reads and writes should be started
until reset is done. Setting this bit sets the RST bit in the
ONEWIRECS register. This bit is self-clearing upon reset
completion.