Target Support Package™ FM5

MIOS Waveform Measurement

Measure pulse width and pulse period measurement via MIOS Double Action Submodule (MDASM)

Library

Target Support Package FM5/ MPC555 Driver Library/ Modular Input/Output System (MIOS1)

Description

Waveform measurement is a feature of the MIOS Double Action Submodule (MDASM) on the MPC555. The MIOS Waveform Measurement block currently implements the following features of the MDASM:

• Pulse width measurement: the MIOS Waveform Measurement block outputs the time from the leading edge of a pulse to the trailing edge of the same pulse.

• Pulse period measurement: the MIOS Waveform Measurement block outputs the time from the leading edge of a pulse to the next leading edge of a pulse.

Note that the minimum and maximum measurable pulse periods and pulse widths are dependent on the selected clock sources and their configurations.

You must configure the clock sources via the MPC555 Resource Configuration object. There are only two clock sources (assigned via the Counter bus parameter) assignable to the 10 MDASM modules. More than one MDASM can be assigned to a single clock source.

Refer to section 15.11, "MIOS Double Action Submodule (MDASM) Registers" in the MPC555 User's Manual for further information on the parameters described below.

Dialog Box

MDASM submodule number

Select one of the 10 MIOS Double Action Submodules (MDASM) in the MPC555.

Measurement

Select the mode of operation of the block: either pulse width measurement or pulse period measurement.

Counter bus

Select one of the two counters that can be used as sources to drive the MDASM module. The counters must be configured via the MPC555 Resource Configuration object. See MIOS1 Configuration Parameters.

Measurement range: [ resolution, max] seconds

This read only field displays the measurement range of the pulse width or pulse period. The example shown is from the MPC555 real-time I/O demo model mpc555rt_io.

Sample time

The period at which Simulink^® reads the pulse width or period. The measurements are performed in hardware so it is not necessary to set the sample time to suit the expected period of the incoming signal.

Invert input polarity

Changes the sense of the leading edge of the pulse. When Invert output polarity is selected, the leading edge is rising. Otherwise, the leading edge is falling.

Hold internal counters when at debug break point (freeze enable)

Stops the clocks of the MDASM module when a breakpoint is hit during debug mode.

MIOS Pulse Width Modulation Out

MPC555 Execution Profiling via CAN A