PXR40RM Datasheet, PDF (760/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Enhanced Modular Input/Output Subsystem (eMIOS200)
23.4 Functional Description
The eMIOS200 provides independently operating unified channels (UC) that can be configured and
accessed by a host MCU. The five time bases can be shared by the channels through five counter buses
and each unified channel can generate its own time base.
The eMIOS200 block is reset asynchronously. All registers are cleared on reset.
23.4.1 Unified Channel (UC)
Figure • shows the unified channel block diagram.Each unified channel consists of:
• Counter bus selector, which selects the time base to be used by the channel for all timing functions
• A programmable clock prescaler
• Two double-buffered data registers, A and B, that allow up to two input capture and/or output
compare events to occur before software intervention is needed
• Two comparators (equal only), A and B, which compare the selected counter bus with the value in
the data registers
• Internal counter, which can be used as a local time base or to count input events
• Programmable input filter, which ensures that only valid pin transitions are received by channel
• Programmable input edge detector, which detects the rising, falling or either edges
• An output flip-flop, which holds the logic level to be applied to the output pin
• eMIOS200 status and control register
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PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor