EDMA3 Registers
11.4.1.6.3
Event Set Registers (ESR, ESRH)
The event set registers (ESR/ESRH) allow the CPU (EDMA3 programmers) to manually set events to
initiate DMA transfer requests. CPU writes of 1 to any event set register (En) bits set the corresponding
bits in the registers. The set event is evaluated by the EDMA3CC logic for an associated transfer request
submission to the transfer controllers. Writing a 0 has no effect.
The event set registers operate independent of the event registers (ER/ERH), and a write of 1 is always
considered a valid event regardless of whether the event is enabled (the corresponding event bits are set
or cleared in EER.En/EERH.En).
Once the event is set in the event set registers, it cannot be cleared by CPU writes, in other words, the
event clear registers (ECR/ECRH) have no effect on the state of ESR/ESRH. The bits will only be cleared
once the transfer request corresponding to the event has been submitted to the transfer controller. The
setting of an event is a higher priority relative to clear operations (via hardware). If set and clear conditions
occur concurrently, the set condition wins. If the event was previously set, then EMR/EMRH would be set
because an event is lost. If the event was previously clear, then the event remains set and is prioritized for
submission to the event queues.
Manually-triggered transfers via writes to ESR/ESRH allow the CPU to submit DMA requests in the
system, these are relevant for memory-to-memory transfer scenarios. If the ESR.En/ESRH.En bit is
already set and another CPU write of 1 is attempted to the same bit, then the corresponding event is
latched in the event missed registers (EMR.En/EMRH.En = 1).
The ESR is shown in
and described in
. The ESRH is shown in
and
described in
Figure 11-74. Event Set Register (ESR)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
E31
E30
E29
E28
E27
E26
E25
E24
E23
E22
E21
E20
E19
E18
E17
E16
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
E15
E14
E13
E12
E11
E10
E9
E8
E7
E6
E5
E4
E3
E2
E1
E0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
RW-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 11-58. Event Set Register (ESR) Field Descriptions
Bit
Field
Value
Description
31-0
En
Event set for event 0-31.
0
No effect.
1
Corresponding DMA event is prioritized versus other pending DMA/QDMA events for submission to the
EDMA3TC.
972
Enhanced Direct Memory Access (EDMA)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated