mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 401

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

If the free run/restart bit (DTMRn[FRR]) is set, a new count starts. If it is clear, the timer keeps running.
21.3.4
When a timer reaches the reference value selected by DTRR, it can send an output signal on DTOUTn.
DTOUTn can be an active-low pulse or a toggle of the current output, as selected by the DTMRn[OM] bit.
21.4
The general-purpose timer modules typically, but not necessarily, follow this program order:
21.4.1
The following code provides an example of how to initialize and use DMA Timer0 for counting time-out
periods.
DTMR0 EQU IPSBARx+0x400 ;Timer0 mode register
DTMR1 EQU IPSBARx+0x440 ;Timer1 mode register
DTRR0 EQU IPSBARx+0x404 ;Timer0 reference register
DTRR1 EQU IPSBARx+0x444 ;Timer1 reference register
DTCR0 EQU IPSBARx+0x408 ;Timer0 capture register
DTCR1 EQU IPSBARx+0x448 ;Timer1 capture register
DTCN0 EQU IPSBARx+0x40C ;Timer0 counter register
DTCN1 EQU IPSBARx+0x44C ;Timer1 counter register
DTER0 EQU IPSBARx+0x403 ;Timer0 event register
DTER1 EQU IPSBARx+0x443 ;Timer1 event register
* TMR0 is defined as: *
*[PS] = 0xFF,
Freescale Semiconductor
•
•
•
•
•
The DTMRn and DTXMRn registers are configured for the desired function and behavior.
— Count and compare to a reference value stored in the DTRRn register
— Capture the timer value on an edge detected on DTINn
— Configure DTOUTn output mode
— Increment counter by 1 or by 65,537 (16-bit mode)
— Enable/disable interrupt or DMA request on counter reference match or capture edge
The DTMRn[CLK] register is configured to select the clock source to be routed to the prescaler.
— Internal bus clock (can be divided by 1 or 16)
— DTINn, the maximum value of DTINn is 1/5 of the internal bus clock, as described in the
The 8-bit DTMRn[PS] prescaler value is set.
Using DTMRn[RST], counter is cleared and started.
Timer events are managed with an interrupt service routine, a DMA request, or by a software
polling mechanism.
Initialization/Application Information
device’s electrical characteristics
Output Mode
Code Example
DTINn may not be configured as a clock source when the timer capture
mode is selected or indeterminate operation results.
divide clock by 256
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
NOTE
DMA Timers (DTIM0–DTIM3)
21-9