---
name: "charge_pump"
section: "9"
platform: "linux"
package: "linuxcnc-uspace"
version: "1:2.9.4-2+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/charge_pump"
---

# charge\_pump(9)

Create a square-wave for the 'charge pump' input of some controller boards

## NAME

charge\_pump - Create a square-wave for the 'charge pump' input of some controller boards

## SYNOPSIS

**loadrt charge\_pump**

## DESCRIPTION

The 'Charge Pump' should be added to the base thread function. When enabled the output is on for one period and off for one period. To calculate the frequency of the output 1/(period time in seconds x 2) = Hz. For example if you have a base period of 100,000ns that is 0.0001 seconds and the formula would be 1/(0.0001 x 2) = 5,000 Hz or 5 kHz. Two additional outputs are provided that run a factor of 2 and 4 slower for hardware that requires a lower frequency.

## FUNCTIONS

- **charge-pump**

  Toggle the output bit (if enabled)

## PINS

- **charge-pump.out bit out**

  Square wave if 'enable' is TRUE or unconnected, low if 'enable' is FALSE

- **charge-pump.out-2 bit out**

  Square wave at half the frequency of 'out'

- **charge-pump.out-4 bit out**

  Square wave at a quarter of the frequency of 'out'

- **charge-pump.enable bit in (default: *TRUE*)**

  If FALSE, forces all 'out' pins to be low

## AUTHOR

Jeff Epler

## LICENSE

GPL