PULSE - One-shot pulse delay and stretch¶

A PULSE block produces configurable width output pulses with an optional delay based on its parameters. If WIDTH is non-zero, the output pulse width will be the specified amount. If DELAY is non-zero, the pulse train will be delayed by that amount. If both are non-zero, the pulses are stretched and delayed as long as the resulting output would still contain the same number of distinct pulses. If this is not the case, then the PERR signal is raised, and the MISSED_CNT counter is incremented. Change of any parameter causes the block to be reset.

Fields¶

Name	Type	Description
DELAY	time	Output pulse delay (0 for no delay)
WIDTH	time	Output pulse width (0 for input pulse width)
ENABLE	bit_mux	Reset on falling edge, enable on rising
TRIG	bit_mux	Input pulse train
OUT	bit_out	Output pulse train
QUEUED	read uint 1023	Length of the delay queue
DROPPED	read	Number of pulses not produced because of an ERR condition
TRIG_EDGE	param enum	INP trigger edge 0 Rising 1 Falling 2 Either

Zero Delay¶

If DELAY=0, then the INP pulse will be stretched with only the propagation delay of the block (1 clock tick). WIDTH must be at least 4, and any value given below is defaulted to four.

(Source code, png, hires.png, pdf)

(Source code, png, hires.png, pdf)

Zero Width¶

If WIDTH=0, then the INP pulse width will be used. DELAY must be >3 clock ticks, any lower inputted values will be defaulted to four.

(Source code, png, hires.png, pdf)

(Source code, png, hires.png, pdf)

Width and Delay¶

In this mode, pulses are placed onto an output queue, so a number of restrictions apply:

There must not be more than 1023 pulses on the output queue
WIDTH must be >3 clock ticks
There must be >3 clock ticks where output is 0 between pulses. This means that WIDTH < T - 3 where T is the minimum INP pulse period

(Source code, png, hires.png, pdf)