Datasheet
PIE
HRCAPx
SYSCLK
PLLCLK
HRCAPxENCLK
HRCAPxINTn
HRCAP Calibration Logic
EPWMxAEPWMx HRPWM
HRCAP Calibration Signal (Internal)
GPIO
Mux
HRCAPx
Module
TMS320F28030, TMS320F28031, TMS320F28032
TMS320F28033, TMS320F28034, TMS320F28035
SPRS584J –APRIL 2009–REVISED OCTOBER 2013
www.ti.com
4.11 High-Resolution Capture (HRCAP) Module
The High-Resolution Capture (HRCAP) module measures the difference between external pulses with a
typical resolution of 300 ps.
Uses for the HRCAP include:
• Capactive touch applications
• High-resolution period and duty cycle measurements of pulse train cycles
• Instantaneous speed measurements
• Instantaneous frequency measurements
• Voltage measurements across an isolation boundary
• Distance/sonar measurement and scanning
The HRCAP module features include:
• Pulse width capture in either non-high-resolution or high-resolution modes
• Difference (Delta) mode pulse width capture
• Typical high-resolution capture on the order of 300 ps resolution on each edge
• Interrupt on either falling or rising edge
• Continuous mode capture of pulse widths in 2-deep buffer
• Calibration logic for precision high-resolution capture
• All of the above resources are dedicated to a single input pin
• HRCAP calibration software library supplied by TI is used for both calibration and calculating fractional
pulse widths
The HRCAP module includes one capture channel in addition to a high-resolution calibration block, which
connects internally to the last available ePWMxA HRPWM channel when calibrating (that is, if there are
eight ePWMs with HRPWM capability, it will be HRPWM8A).
Each HRCAP channel has the following independent key resources:
• Dedicated input capture pin
• 16-bit HRCAP clock which is either equal to the PLL output frequency (asynchronous to SYSCLK) or
equal to the SYSCLK frequency (synchronous to SYSCLK)
• High-resolution pulse width capture in a 2-deep buffer
Figure 4-15. HRCAP Functional Block Diagram
90 Peripherals Copyright © 2009–2013, Texas Instruments Incorporated
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