PXR40RM Datasheet, PDF (808/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Enhanced Modular Input/Output Subsystem (eMIOS200)
System Clock
Input Event
Internal Counter
1
2
30
1
2
30
1
2
Match Value = 3
See Note
FLAG Set Event
FLAG Pin/Register
FLAG Clear
Note: When a match occurs, the first system clock cycle is used to clear the internal counter, and at the next edge
of prescaler clock enable the counter will start counting.
Figure 23-63. Time Base Generation with External Clock and Clear on Match Start
PRESCALED CLOCK RATIO = 3
System Clock
Prescaler Clock Enable
Internal Counter
1
2
30
0
1
2
30
0
Match Value = 3
See Note
FLAG Set Event
FLAG Pin/Register
FLAG Clear
Note: When a match occurs, the first clock cycle is used to clear the internal counter,
and only after a second edge of prescaled clock the counter will start counting.
Figure 23-64. Time Base Generation with Internal Clock and Clear on Match Start
PRESCALED CLOCK RATIO = 3
System Clock
Input Event/
Prescaler Clock Enable
Internal Counter
1
2
3
0
1
2
3
0
Match Value = 3
FLAG Set Event
See Note
FLAG Pin/Register
FLAG Clear
Note: The match occurs only when the input event/prescaler clock enable is active.
Then, the internal counter is immediately cleared.
Figure 23-65. Time Base Generation with Clear on Match End
23-68
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor