Pulse-Width Modulation Subsystem (PWMSS)
15.1 Pulse-Width Modulation Subsystem (PWMSS)
15.1.1 Introduction
15.1.1.1 Features
The general features of the PWMSS are:
eHRPWM
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Dedicated 16 bit time-base with Period / Frequency control
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Can support 2 independent PWM outputs with Single edge operation
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Can support 2 independent PWM outputs with Dual edge symmetric operation
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Can support 1 independent PWM output with Dual edge asymmetric operation
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Supports Dead-band generation with independent Rising and Falling edge delay control
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Provides asynchronous over-ride control of PWM signals during fault conditions
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Supports “trip zone” allocation of both latched and un-latched fault conditions
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Allows events to trigger both CPU interrupts and start of ADC conversions
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Support PWM chopping by high frequency carrier signal, used for pulse transformer gate drives.
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High-resolution module with programmable delay line.
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Programmable on a per PWM period basis.
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Can be inserted either on the rising edge or falling edge of the PWM pulse or both or not at all.
eCAP
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Dedicated input Capture pin
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32 bit Time Base (counter)
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4 x 32 bit Time-stamp Capture registers (CAP1-CAP4)
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4 stage sequencer (Mod4 counter) which is synchronized to external events (ECAPx pin edges)
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Independent Edge polarity (Rising / Falling edge) selection for all 4 events
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Input Capture signal pre-scaling (from 1 to 16)
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One-shot compare register (2 bits) to freeze captures after 1 to 4 Time-stamp events
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Control for continuous Time-stamp captures using a 4 deep circular buffer (CAP1-CAP4) scheme
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Interrupt capabilities on any of the 4 capture events
eQEP
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Input Synchronization
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Three Stage/Six Stage Digital Noise Filter
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Quadrature Decoder Unit
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Position Counter and Control unit for position measurement
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Quadrature Edge Capture unit for low speed measurement
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Unit Time base for speed/frequency measurement
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Watchdog Timer for detecting stalls
1486
Pulse-Width Modulation Subsystem (PWMSS)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated