AN2577 Datasheet, PDF (1/34 Pages) STMicroelectronics – Using the eTPU angle clock

AN2577
Application note
Using the eTPU angle clock
Introduction
This document describes the angle clock feature of the enhanced time processor unit and
offers practical advise on the application and use of this feature. The note assumes a
familiarity with the eTPU and the eTPU_C language used in the byte craft compiler.
The eTPU is particularly suited to applications where input and output actions are
synchronized to the position of a rotating wheel. The eTPU angle clock provides hardware
which, when combined with the proper software, can track the wheel angle through
accelerations, decelerations, and a wide range of speeds.
If a wheel is tracked by the eTPU angle clock, many output matches and input captures can
operate on an angle count as well as a time count, and even on combinations of the two.
Compensation for speed changes are made in the angle clock only. An angle triggered
event will occur on the best estimate of the match angle.
The angle clock is complex to set up, but when running it offers an excellent integration of
fast operating hardware with the complex control of a software program. A reference design
has been built to demonstrate the operation of a periodic angle clock with other engine
control functions. See your STMicroelectronics representative for details.
September 2013
Rev 2
1/34
www.st.com