Digital Signal Source
In this topic:
Netlist entry
Axxxx [ out_0 out_1 .. out_n ] model_name
Connection details
| Name | Description | Flow | Type |
| out | Output | out | d, vector |
Model format
.MODEL model_name d_source parameters
Model parameters
| Name | Description | Type | Default | Limits |
| input_file | Digital input vector filename | string | none | none |
| out_family | Output logic family | string | UNIV | none |
| out_res | Digital output resistance | real | 100 | ???MATH???0 - \infty???MATH??? |
| out_res_pos | Digital output res. pos. slope | real | out_res | ???MATH???0 - \infty???MATH??? |
| out_res_neg | Digital output res. neg. slope | out_res | ???MATH???0 - \infty???MATH??? | |
| min_sink | Minimum sink current | real | -0.001 | none |
| max_source | Maximum source current | real | 0.001 | none |
Device Operation
The digital signal source provides a multi bit arbitrary digital signal defined in a file.
File Format
The file is in ASCII format and is in the form of a table each row being on a new line. The first column defines the time values while the entries in the remaining columns define the output value for each of the outputs. So the total number of columns must be the number of outputs plus one. The output values must appear in the same order as the outputs in the netlist entry. So, the values for out_0 will be in column 2, out_1 in column 3 etc.
The file may include blank lines and comment lines beginning with a '*'.
The output values must specify the state as well as the strength using the following codes:
| Code | State-Strength |
| 0S | LOW-STRONG |
| 1S | HIGH-STRONG |
| US | UNKNOWN-STRONG |
| 0R | LOW-RESISTIVE |
| 1R | HIGH-RESISTIVE |
| UR | UNKNOWN-RESISTIVE |
| 0Z | LOW-HI-Z |
| 1Z | HIGH-HI-Z |
| UZ | UNKNOWN-HI-Z |
| 0U | LOW-UNDETERMINED |
| 1U | HIGH-UNDETERMINED |
| UU | UNKNOWN-UNDETERMINED |
Example
The following file:
* This is an example source file 0.0 0s 0s 0r 1s 1u 0s 0s 0r 0z 2u 0s 0s 1r 0z 5u 1s 0s 1r 0z 22e-6 1s 1s 1r 0z 50u 0s 1s 1r 0z 60u 0s 1s 1r 0z 70u 0s 1s 1r 0z 80u 0s 1s 1r 0z 90u Us Us Ur 0s
and this circuit:
Produces the following waveforms
An error will result if the file fails in any way to comply with the format. There must be the exact number of entries in each row and the time values must be monotonic. Totally blank lines or lines containing only white space are permitted but any other non-comment line not complying with the format will fail.
| ◄ Digital Pulse | Inverter ▶ |