DMA Timers (DTIM0–DTIM3)
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
21-6
Freescale Semiconductor
Preliminary
21.2.4
DMA Timer Reference Registers (DTRR
n
)
Each DTRR
n
, contains the reference value compared with the respective
free-running timer counter (DTCN
n
) as part of the output-compare function. The reference value is not
matched until DTCN
n
equals DTRR
n
, and the prescaler indicates that DTCN
n
should be incremented
again. Therefore, the reference register is matched after DTRR
n
+ 1 time intervals.
Table 21-4. DTER
n
Field Descriptions
Field
Description
7–2
Reserved, must be cleared.
1
REF
Output reference event. The counter value, DTCN
n,
equals the reference value, DTRR
n
. Writing a 1 to REF clears
the event condition. Writing a 0 has no effect.
0
CAP
Capture event. The counter value has been latched into DTCR
n
. Writing a 1 to CAP clears the event condition.
Writing a 0 has no effect.
REF
DTMR
n
[ORRI]
DTXMR
n
[DMAEN]
0
X
X
No event
1
0
0
No request asserted
1
0
1
No request asserted
1
1
0
Interrupt request asserted
1
1
1
DMA request asserted
CAP
DTMR
n
[CE]
DTXMR
n
[DMAEN]
0
XX
X
No event
1
00
0
Disable capture event output
1
00
1
Disable capture event output
1
01
0
Capture on rising edge & trigger interrupt
1
01
1
Capture on rising edge & trigger DMA
1
10
0
Capture on falling edge & trigger interrupt
1
10
1
Capture on falling edge & trigger DMA
1
11
0
Capture on any edge & trigger interrupt
1
11
1
Capture on any edge & trigger DMA