HRCAP

Capture pulse width in normal or high resolution modes for F2803x and F2806x processors

Since R2023b

• 

Libraries:
C2000 Microcontroller Blockset / C2803x
C2000 Microcontroller Blockset / C2806x

Description

Use the high resolution capture (HRCAP) block to capture the pulse width in the normal or high resolution modes and perform conventional and high resolution delta time measurements. The block uses the HRCAP type 0 module for F2803x and F2806x processors.

Note

You can enable high resolution mode (HRCAP mode) using eCAP block for TI F28002x, F28003x, F28004x, F2838x, and F28P65x processors. For more, see C28x eCAP

You can operate the block in normal or high resolution mode. In high resolution mode, the calibration function uses additional HRCAP and HRPWM modules internally in the ePWM module. The block supports only the PLL clock in the high resolution mode and uses the PLLCLK or PLL2CLK as the PLL clock source based on the processor.

The block does not support SYSCLK in the high resolution mode. For the block to calibrate the output, the clock frequency has to be higher than 98 MHz, and the maximum SYSCLK frequency for the F2806x is 90MHz and F2803x boards is 60MHz.

For high resolution mode, only PLL clock is supported and clock frequency should be in the range between 98 to 120 MHz for calibration.

Output in high resolution mode will be in counts of HCCAPCLK (16-bit HRCAP clock) cycles in Q16 format and output in normal mode will be vector outputs for rise (0,1) and fall (0,1) signals which can be in microseconds or HRCAPCLK cycles.

Examples

Using HRCAP to Capture Input Signals

Use high resolution capture (HRCAP) Block to capture the input signals using C2000™ Microcontroller Blockset.

Open Script

Ports

Output

Rise[0,1] — Output capture value

vector

The block outputs two consecutive On time values. On time values corresponds to the time between rising and falling edge.

Dependencies

To enable this port, set the HRCAP mode parameter to Normal.

Data Types: uint16

Fall[0,1] — Output capture value

vector

The block outputs two consecutive Off time values. Off time values corresponds to the time between falling and rising edge.

Dependencies

To enable this port, set the HRCAP mode parameter to Normal.

Data Types: uint16

CounterOverflow — Overflow status

scalar

The value of 0 indicates that counter has not overflowed. 1 indicates that the counter has overflowed from the highest value to 0.

Dependencies

To enable this port, set the HRCAP mode to Normal and select the Enable counter overflow output parameter.

Data Types: uint16

Period — Output capture data

scalar

The block outputs the value period of the waveform. This is sum of on and off time.

Dependencies

To enable this port, set the HRCAP mode parameter to High resolution and HRCAP output to either Period only or All above(Period, On, Off).

Data Types: Fixed point[0,16,16] | uint32

On — Output capture data

scalar

The block outputs the value of On continuously. On time values corresponds to the time between rising and falling edge.

Dependencies

To enable this port, set the HRCAP mode parameter to High resolution and HRCAP output to either On time only or All above(Period, On, Off).

Data Types: Fixed point[0,16,16] | uint32

Off — Output capture data

scalar

The block outputs the value of Off continuously. Off time values corresponds to the time between falling and rising edge.

Dependencies

To enable this port, set the HRCAP mode parameter to High resolution and HRCAP output to either Off time only or All above(Period, On, Off).

Data Types: Fixed point[0,16,16] | uint32

Parameters

HRCAP module — Select HRCAP module

HRCAP1 (default) | HRCAP2 | HRCAP3 | HRCAP4

Select the HRCAP module which captures the input signal.

HRCAP mode — Select HRCAP mode

Normal (default) | High resolution

Select the HRCAP mode.

You can operate the HRCAP block in the normal or the high resolution mode. In high resolution mode, the calibration function uses additional HRCAP module and HRPWM in ePWM module internally.

The unused HRCAP module is used for calibration and HRPWM of highest instance is used for calibration.

For calibration, the block utilizes unused HRCAP module and largest instance of HRPWM module. Additionally, this calibration process is executed continuously in the background.

HRCAP clock — Select HRCAP clock

SYSCLKOUT (default) | PLL clock

Select the HRCAP clock for normal HRCAP mode. You can either select SYSCLKOUT or PLL clock when set to normal mode.

PLL clock is the only clock that is supported in high resolution mode and uses PLLCLK or PLL2CLK based on the processor.

Dependencies

To enable this parameter, set the HRCAP mode parameter to Normal.

Enable rising edge interrupt — Enable interrupt when rising edge is detected

on (default) | off

Select this parameter when rising edge interrupt is detected for the HRCAP block.

Enable falling edge interrupt — Enable interrupt when falling edge is detected

on (default) | off

Select this parameter when falling edge interrupt is detected for the HRCAP block.

Enable counter overflow interrupt — Enable interrupt when counter overflow is detected

off (default) | on

Select this parameter to when counter overflow interrupt is detected for HRCAP block.

Output type — Select output data type

HRCAPCLK cycles (default) | Microseconds | uint32 | fixdt(0,16,16)

Select the output type for the HRCAP in the normal mode and high resolution mode. When you set Output type to uint32, the data is in Q16 format.

Enable counter overflow output — Select to capture HCCOUNTER overflows

off (default) | on

enable the counter overflow interrupt. The block outputs the HCCOUNTER overflow status at the CounterOverflow output port.

Dependencies

To enable this parameter, set the HRCAP mode parameter to Normal.

HRCAP output — High resolution HRCAP output

Period only (default) | ON time only | Off time only | On and Off time | All above(Period, On time, Off time )

Select the required high resolution outputs. HRCAP output parameter will configure the ports Period, On, Off or All above (Period, On time, Off time).

Dependencies

To enable this parameter, set the HRCAP mode parameter to High resolution.

Sample time — Frequency at which block reads data from HRCAP

0.1 (default)

Use this parameter to specify the time interval between samples. To inherit sample time from an upstream block, set this parameter to -1.

Version History

Introduced in R2023b