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Introduction
41.2 Introduction
The enhanced quadrature Encoder/ decoder module provides interfacing capability to
position/speed sensors used in industrial motor control applications. It has five input
signals: PHASEA, PHASEB, INDEX, TRIGGER, and HOME. This module is used to
decode shaft position, revolution count and speed.
41.2.1 Features
• Includes logic to decode quadrature signals
• Configurable digital filter for inputs
• 32-bit position counter capable of modulo counting
• 16-bit position difference register
• Maximum count frequency equals the peripheral clock rate
• Position counter can be initialized by software or external events
• Preloadable 16-bit revolution counter
• Inputs can be connected to a general purpose timer to aid low speed velocity
measurements
• Quadrature decoder filter can be bypassed
• A watchdog timer to detect a non-rotating shaft condition
• Compare function to indicate when shaft has reached a defined position
• Optional interrupt when both PHASEA and PHASEB inputs change in the same
cycle
41.2.2 Decoder Block Diagram
The following figure shows the block diagram of the quadrature decoder module.
1040
KV4x Reference Manual, Rev. 2, 02/2015
Preliminary
Freescale Semiconductor, Inc.
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