LM3S2B93 Datasheet, PDF (389/1194 Pages) Texas Instruments – Stellaris® LM3S2B93 Microcontroller

Stellaris^® LM3S2B93 Microcontroller
Register 4: DMA Status (DMASTAT), offset 0x000
The DMA Status (DMASTAT) register returns the status of the μDMA controller. You cannot read
this register when the μDMA controller is in the reset state.
DMA Status (DMASTAT)
Base 0x400F.F000
Offset 0x000
Type RO, reset 0x001F.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
DMACHANS
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
STATE
reserved
MASTEN
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:21
20:16
15:8
7:4
Name
reserved
DMACHANS
reserved
STATE
Type
RO
RO
RO
RO
Reset
0x000
0x1F
0x00
0x0
Description
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Available μDMA Channels Minus 1
This field contains a value equal to the number of μDMA channels the
μDMA controller is configured to use, minus one. The value of 0x1F
corresponds to 32 μDMA channels.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Control State Machine Status
This field shows the current status of the control state machine. Status
can be one of the following.
Value Description
0x0
Idle
0x1
Reading channel controller data.
0x2
Reading source end pointer.
0x3
Reading destination end pointer.
0x4
Reading source data.
0x5
Writing destination data.
0x6
Waiting for µDMA request to clear.
0x7
Writing channel controller data.
0x8
Stalled
0x9
Done
0xA-0xF Undefined
3:1
reserved
RO
0x0
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
January 20, 2012
389
Texas Instruments-Production Data