ppreset

ppreset pulses the FPGA S2F reset and resets streamer 1 through the normal single-streamer bring-up path.

Use it when you want to return the primary streamer to a known idle state after an aborted run, an infinite/retriggered sequence, a manual trigger experiment, or a command that intentionally skipped normal cleanup.

Syntax

ppreset [options]

What It Does

ppreset uses the same shared startup path as the other pptool-family commands, then constructs the standard single-streamer helper.

The command:

  • applies any requested clock or PLL changes during the normal startup sequence
  • always performs an FPGA S2F reset during startup, equivalent to passing -reset_FPGA
  • programs the streamer initial output value, defaulting to 0
  • asserts the physical output enable (oe)
  • restores the streamer's software-visible control word to its persistent defaults
  • pulses the streamer reset bit

This is a streamer/runtime reset, not a bitstream reload. It does not reprogram pulsepins.rbf, and it does not directly reset readback or counter state.

ppreset is not a high-impedance operation: it asserts physical output enable and actively drives the selected -i value. To stop the streamer at zero and then release the bidirectional qout, qout_valid, and qout_strobe pins before connecting another driver, use:

ppreset -i 0x0
ppread -oe 0 -hard-timeout 100ms

The bounded ppread invocation changes oe to input mode and exits after the hard timeout; power-down is an alternative when changing wiring.

Common Options

Streamer reset options:

  • -i VALUE: set the idle/initial output value used after reset

Shared startup options that are often relevant before a reset:

  • -core_pll PROFILE: configure core_clk
  • -int_pll PROFILE: configure the internal candidate streamer clock
  • -int_clk: select the internal streamer clock path
  • -ext_clk: select the external streamer clock path
  • -clk N: select a raw clock mux value
  • -reset_FPGA: accepted for consistency; ppreset performs this reset even when the option is omitted
  • -dark_mode: disable status LEDs during startup

Expected Output

On success, ppreset prints the usual startup/version and frequency-meter information, then exits with the shared success return code:

All done, exiting with return code 0

If -i is set to a non-zero value, the command also reports the configured initial value before pulsing reset.

Troubleshooting

Use ppreset when trigger force/enable state, qout override state, or streamer status appears stale after manual experiments.

If the streamer still does not return to a usable state, reload the FPGA image with FPGA-writeConfig -f pulsepins.rbf.

If outputs come up at the wrong idle value, pass the intended pattern explicitly with -i VALUE.

For follow-up diagnosis, use: