A breakpoint is basically a tool that allows you to simulate a circuit with the ability to stop it when certain conditions occur.
The initial state of the breakpoint can be set during the Setup of the interactive simulation or through the INIT parameter. During the interactive simulation the state of the breakpoint can be changed by clicking on it with left button of the mouse.
Parameters
| Parameter | Description | Default |
|---|---|---|
| INIT | Specifies the initial state of the breakpoint. | ON |
| AUTOTRIGGER | In AutoTrigger mode the breakpoint is reactivated automatically when you resume the simulation of the circuit. | OFF |
| EXPRESSION | Specify the conditions that determine when a circuit's simulation should be interrupted. | |
| IOMODEL | The name of an I/O model, which describes the device’s loading and driving characteristics. | DGTDEFIOMODEL |
| POWER_NODE | Digital power node name. Is the node used by the interface subcircuits which connect analog nodes to digital nodes. | $G_DPWR |
| GROUND_NODE | Digital ground node name. Is the node used by the interface subcircuits which connect analog nodes to digital nodes. | $G_DGND |
Description
The parameter EXPRESION specify the conditions that determine when a simulation should be interrupted. Special variables are defined that allow access to some of the values of the current simulation.
Special variables for digital breakpoints
For digital breakpoints are defined the global variable BUS and 19 variables for each pin.
The BUS variable returns the binary value present at the pins of the breakpoint.
The variable names associated with the pins have the following form:
| <functionName>_<pinName> |
The first part of the name is the function name followed by an underscore. The second part of the name is formed by the name of the pin. The functions are listed in the following table.
| Function | Description |
|---|---|
| IsLow | The value is 1 if the state of the specified pin is Low otherwise the value is 0. |
| IsHigh | The value is 1 if the state of the specified pin is High otherwise the value is 0. |
| IsHiZ | The value is 1 if the specified pin is in High-Impedance otherwise the value is 0. |
| IsUndef | The value is 1 if the state of the specified pin is undetermined otherwise the value is 0. |
| IsLH | The value is 1 for low to high transition otherwise the value is 0. |
| IsLX | The value is 1 for low to other transition otherwise the value is 0. |
| IsLZ | The value is 1 for low to hi-impedance transition otherwise the value is 0. |
| IsHL | The value is 1 for high to low transition otherwise the value is 0. |
| IsHX | The value is 1 for high to other transition otherwise the value is 0. |
| IsHZ | The value is 1 for high to hi-impedance transition otherwise the value is 0. |
| IsXL | The value is 1 for other to low transition otherwise the value is 0. |
| IsXH | The value is 1 for other to high transition otherwise the value is 0. |
| IsXZ | The value is 1 for other to hi-impedance transition otherwise the value is 0. |
| IsZL | The value is 1 for hi-impedance to low transition otherwise the value is 0. |
| IsZH | The value is 1 for hi-impedance to high transition otherwise the value is 0. |
| IsZX | The value is 1 for hi-impedance to other transition otherwise the value is 0. |
| IsXX | The value is 1 for transition otherwise the value is 0. |
| ChangeTime | Returns time when the specified pin last changed state. |
| PulseWidth | Returns last pulse width for the specified pin. |
Special variables for analog breakpoint
For analog breakpoints the following variables are defined:
| Variable | Description |
|---|---|
| voltage | Returns the input voltage. |
| current | Returns the input current. |
Examples
isXH_D0 :Test for transition on pin D0.
(isLow_D0) && (isHL_D1) :Test for high to low transition on pin D1 when pin D0 is low.
voltage > 1.3 :Pause the simulation if the voltage exceeds 1.3 volts.
current < 1m :Pauses the simulation if the current is less than 1 mA.