Control Registers and Control Packets
724
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Direct Memory Access Controller (DMA) Module
20.3.1 Global Configuration Registers
These registers control the overall behavior of the DMA controller.
20.3.1.1 Global Control Register (GCTRL)
Figure 20-19. Global Control Register (GCTRL) [offset = 00]
31
17
16
Reserved
DMA_EN
R-0
R/WP-0
15
14
13
10
9
8
Reserved
BUS_BUSY
Reserved
DEBUGMODE
R-0
R-0
R-0
R/WP-0
7
1
0
Reserved
DMARES
R-0
R/WP-0
LEGEND: R/W = Read/Write; R = Read only; WP = Write in privilege mode only; -
n
= value after reset
Table 20-9. Global Control Register (GCTRL) Field Descriptions
Bit
Field
Value
Description
31-17
Reserved
0
Reads return 0. Writes have no effect.
16
DMA_EN
DMA enable bit. The configuration registers and channel control packets should be setup first
before DMA_EN bit is set to one to prevent state machines from carrying out bus transactions.
If DMA_EN bit is cleared in the middle of an bus transaction, the state machine will stop at an
arbitration boundary.
0
The DMA is disabled.
1
The DMA is enabled.
15
Reserved
0
Reads return 0. Writes have no effect.
14
BUS_BUSY
This bit indicates status of DMA external AHB bus status.
0
DMAs external bus is not busy in data transfers.
1
DMAs external bus is busy in data transfers.
13-10
Reserved
0
Reads return 0. Writes have no effect.
9-8
DEBUGMODE
Debug Mode.
0
Ignore suspend.
1h
Finish current block transfer.
2h
Finish current frame transfer.
3h
Immediately stop at an DMA arbitration boundary and continue after suspend.
7-1
Reserved
0
Reads return 0. Writes have no effect.
0
DMARES
DMA software reset.
Note:
In the event a DMA slave does not respond, the DMA module will respond to the
software reset upon reaching an arbitration boundary.
0
Read: Software reset is disabled.
Write: No effect.
1
Read and write: The DMA state machine and all control registers are in software reset. Control
packets are not reset when DMA software reset is active.