GoldExI : FAQ : Programming a waveform

Question

How do I program a waveform?

Answer

In main menu select Tools | Program waveform | <number> . You will see the window with the following fields:

Sequence -- describes the waveform using a pseudo-code. For example: the following sequence "00100" describes the waveform consisting of 5 logical units (LUs): zero, zero, one, zero, zero, i.e. the signal stays zero during 2 LUs, then jumps to 1, stays at 1 for 1 LU, and then jumps back to zero and stays so for 2 LUs. The following LUs (symbols which can be used in waveform description) are currently defined:
0 -- logical zero
1 -- logical one
_ -- logical zero (the same as 0)
/ -- ramp from 0 to 1 during 1 LU
\ -- ramp from 1 to 0 during 1 LU
T -- triangle-like up-down ramp (looks like /\) from 0 to 1 and back to 0 during 1 LU
| -- pulse 1/4 of LU it is 0, next 1/2 of LU it is 1, the last 1/4 of LU it is zero. It is like sequence "0110" compressed 4 times to fit into 1 LU.

If you need other kinds of LUs you can write me an e-mail with suggestions.
Stretch -- allows you to stretch (or squeeze) waveform in time by a given number of times. Stretch >1 corresponds to stretching, stretch<1 corresponds to squeezing. Note, that different waveforms can be stretched differently, thus giving you a freedom to construct virtually any combination of waveforms.
Value of "0" and Value of "1" -- allow to set the value of logical 0 and 1. This should be in the range from -1 up to 1. The value equal to 1.0 corresponds to the full current amplitude, 0.5 corresponds to the half of the current amplitude, etc...
Prolongation -- When you use several waveforms, they may be of different lengths, especially if you stretch some of them. GoldExI always chooses the longest one (after stretching) to determine the time of measurement. In such a situation the following question arises: what should we do with the shorter waveforms? GoldExI gives you 2 possibilities, either
1. prolong the short waveform up to the length of the longest one using logical "0"s, or
2. prolong the short waveform up to the length of the longest one periodically, i.e. it will be repeated from the beginning until it will reach the required length.
This prolongation methods can be specified for each waveform for the case when this waveform will be not the longest. If this waveform happen to be the longest one (after stretching!), the specified prolongation method is ignored because prolongation is not needed.
Randomize -- if this is on, GoldExI will randomly shuffle the symbols (LUs) in waveform description for every measurement. This is useful for final testing of digital circuits using random input sequences.

The waveforms can be used for V(I_wfm) measurements or when GoldExI is used as a functional generator (check "generator" in V(I_wfm) measurement window).