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MOTOROLA
Chapter 21. DMA Timers (DTIM0–DTIM3)
21-3
DMA Timer Programming Model
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
.
21.2.2 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 DTIN
n
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] is set and
DTXMR
n
[DMAEN] is one, a DMA request is asserted. If DTER
n
[CAP] is set and
DTXMR
n
[DMAEN] is zero, an interrupt is asserted.
21.2.3 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 one and DTXMR
n
[DMAEN] is zero, an interrupt
is asserted. If DTMR
n
[ORRI] is one and DTXMR
n
[DMAEN] is one, 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.
21.2.4 Output Mode
When a timer reaches the reference value selected by DTRR, it can send an output signal
on DTOUT
n
. DTOUT
n
can be an active-low pulse or a toggle of the current output as
selected by the TMR
n
[OM] bit.
21.2.5 Memory Map
The timer module registers, shown in Table 21-1, can be modified at any time.
Table 21-1. DMA Timer Module Memory Map
IPSBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x400
DMA Timer0 Mode Register (DTMR0)
DMA Timer0 Extended
Mode Register (DTXMR0)
DMA Timer0 Event
Register (DTER0)
0x404
DMA Timer0 Reference Register (DTRR0)
0x408
DMA Timer0 Capture Register (DTCR0)
0x40C
DMA Timer0 Counter Register (DTCN0)
0x440
DMA Timer1 Mode Register (DTMR1)
DMA Timer1 Extended
Mode Register (DTXMR1)
DMA Timer1 Event
Register (DTER1)
0x444
DMA Timer1 Reference Register (DTRR1)
Содержание ColdFire MCF5281
Страница 1: ...MCF5282UM D Rev 2 1 2004 MCF5282 ColdFire Microcontroller User s Manual Devices Supported MCF5281 ...
Страница 124: ...3 20 MCF5282 User s Manual MOTOROLA EMAC Instruction Set Summary ...
Страница 141: ...MOTOROLA Chapter 5 Static RAM SRAM 5 5 SRAM Programming Model ...
Страница 142: ...5 6 MCF5282 User s Manual MOTOROLA SRAM Programming Model ...
Страница 168: ...6 26 MCF5282 User s Manual MOTOROLA Interrupts ...
Страница 186: ...7 18 MCF5282 User s Manual MOTOROLA Functional Description ...
Страница 228: ...9 22 MCF5282 User s Manual MOTOROLA Functional Description ...
Страница 246: ...10 18 MCF5282 User s Manual MOTOROLA Low Power Wakeup Operation ...
Страница 254: ...11 8 MCF5282 User s Manual MOTOROLA Memory Map and Registers ...
Страница 264: ...12 10 MCF5282 User s Manual MOTOROLA Chip Select Registers ...
Страница 280: ...13 16 MCF5282 User s Manual MOTOROLA Misaligned Operands ...
Страница 314: ...14 34 MCF5282 User s Manual MOTOROLA MCF5282 External Signals ...
Страница 339: ...MOTOROLA Chapter 15 Synchronous DRAM Controller Module 15 25 SDRAM Example ...
Страница 340: ...15 26 MCF5282 User s Manual MOTOROLA SDRAM Example ...
Страница 356: ...16 16 MCF5282 User s Manual MOTOROLA DMA Controller Module Functional Description ...
Страница 408: ...17 52 MCF5282 User s Manual MOTOROLA Buffer Descriptors ...
Страница 446: ...20 24 MCF5282 User s Manual MOTOROLA Interrupts ...
Страница 474: ...22 18 MCF5282 User s Manual MOTOROLA Programming Model ...
Страница 510: ...23 36 MCF5282 User s Manual MOTOROLA Operation ...
Страница 526: ...24 16 MCF5282 User s Manual MOTOROLA I2C Programming Examples ...
Страница 672: ...28 12 MCF5282 User s Manual MOTOROLA Functional Description ...
Страница 718: ...29 46 MCF5282 User s Manual MOTOROLA Motorola Recommended BDM Pinout ...
Страница 750: ...32 8 MCF5282 User s Manual MOTOROLA Ordering Information ...
Страница 800: ...A 22 MCF5282 User s Manual MOTOROLA ...