I want to use the etpu of mpc5644A MCU to implement the function of the input pulse width measurement.before I have never touched the etpu,who can give me some demo about it.
Hi, for your purpose PPA function will be the right one. How PPA function is supposed to be configured and used, it is described is application note AN2858. Its software attachment AN2858SW contains also example code.
http://www.nxp.com/assets/documents/data/en/application-notes/AN2858.pdf
Below there is general answer regarding usage of eTPU, pay attention to point no.1:
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eTPU is an complex I/O co-processor. You can use it two ways:
1) with using of eTPU functions prepared by NXP
2) to create your own function or modify NXP’s function
Ad 1)
For using eTPU functions pre-prepared by NXP (the ones you can download by eTPU Function Selector) without modification you don’t need any eTPU compiler. See
http://www.nxp.com/webapp/etpu/
Also there is some new version, currently containing only some functions:
http://www.nxp.com/webapp/etpu_cw/
Only download them, configure by eTPU graphical configuration tool (GCT), include all needed files to CodeWarrior or other compiler and use it.
GCT is the tool which is intended to configure most of functions prepared by FSL that can be downloaded as a pack here:
Here you can example procedure how to use eTPU PWM function, step by step:
http://www.nxp.com/files/soft_dev_tools/doc/app_note/AN4687.pdf
Every eTPU FUNCTION has its own descriptive documents (application note), its software attachment usually contains some simple example code:
Ad 2)
If you need to write your own function or modify the existing one, you need eTPU compiler - either Freescale eTPU2 Development Suite (it is compiler + simulator)
or Ashware (their compiler and their simulator) or combination of ByteCraft compiler and Ashware simulator. Note that Freescale eTPU2 Development Suite is the newest product from mentioned options.
Typically developing process of eTPU function means using of eTPU compiler and simulator as well as debugger is usually of out game (for instance imagine motor driving when hardly you can put breakpoint to the code during runtime) and it is used to the test of application at the end. Thus debugger will be needed in conjunction CW for MPC55xx/MPC56xx.