
DMA Timers (DTIM0–DTIM3)
29-8
Freescale Semiconductor
29.2.6
DMA Timer Counters (DTCNn)
The current value of the 32-bit timer counter can be read at anytime without affecting counting. Writes to
DTCN
n
clear the timer counter. The timer counter increments on the clock source rising edge (internal bus
clock divided by 1, internal bus clock divided by 16, or DT
n
IN).
29.3
Functional Description
29.3.1
Prescaler
The prescaler clock input is selected from the internal bus clock (f
sys/3
divided by 1 or 16) or from the
corresponding timer input, DT
n
IN. DT
n
IN is synchronized to the internal bus clock, and the
synchronization delay is between two and three internal bus clocks. The corresponding DTMR
n
[CLK]
selects the clock input source. A programmable prescaler divides the clock input by values from 1 to 256.
The prescaler output is an input to the 32-bit counter, DTCN
n
.
29.3.2
Capture Mode
Each DMA timer has a 32-bit timer capture register (DTCR
n
) that latches the counter value when the
corresponding input capture edge detector senses a defined DT
n
IN transition. The capture edge bits
(DTMR
n
[CE]) select the type of transition that triggers the capture and sets the timer event register capture
event bit, DTER
n
[CAP]. If DTER
n
[CAP] and DTXMR
n
[DMAEN] are set, a DMA request is asserted. If
DTER
n
[CAP] is set and DTXMR
n
[DMAEN] is cleared, an interrupt is asserted.
29.3.3
Reference Compare
Each DMA timer can be configured to count up to a reference value, at which point DTER
n
[REF] is set.
If DTMR
n
[ORRI] is set and DTXMR
n
[DMAEN] is cleared, an interrupt is asserted. If DTMR
n
[ORRI]
and DTXMR
n
[DMAEN] are set, a DMA request is asserted. If the free run/restart bit DTMR
n
[FRR] is
set, a new count starts. If it is clear, the timer keeps running.
Address:
0x
FC07_00
0C
(
DTCN0
)
0x
FC07_400
C
(
DTCN1
)
0x
FC07_800
C
(
DTCN2
)
0x
FC07_C00
C
(
DTCN3
)
Access: User read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
CNT (32-bit timer counter value count)
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 29-7. DMA Timer Counters (DTCNn)
Table 29-7. DTCNn Field Descriptions
Field
Description
31–0
CNT
Timer counter. Can be read at anytime without affecting counting and any write to this field clears it.
MCF5329 Reference Manual, Rev 3
Содержание MCF5329
Страница 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 126: ...Enhanced Multiply Accumulate Unit EMAC 4 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 564: ...Liquid Crystal Display Controller LCDC 22 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 692: ...Programmable Interrupt Timers PIT0 PIT3 28 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 720: ...Queued Serial Peripheral Interface QSPI 30 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 790: ...Message Digest Hardware Accelerator MDHA 33 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 902: ...Register Memory Map Quick Reference A 26 Freescale Semiconductor MCF5329 Reference Manual Rev 3...