The DVM Multi-Step Analysis allows you to step a set of design parameters over a range of values using a decade-step or linear-step sequence. You may also step values over a defined list of parameter values. One advantage of using a single test with a multi-step analysis over multiple DVM tests is the multi-core capability which is part of the Pro and Elite license packages. The multi-core capability runs steps in parallel on multiple processor cores and will greatly reduce the simulation time required for the multi-step analysis. Even using a single processor core reduces the required simulation time as the schematic is setup once, as is the graph and data collection after the simulation completes.
The Multi-Step Analysis doesn't determine the actual simulation Objective nor the POP, AC or TRAN Analysis directives, rather, the Multi-Step Analysis specifies that the configured analysis is to be run through one or more parameter steps. The Multi-Step Analysis is configured using an Analysis testplan entry.
In this topic:
The table on the Multi-Step Analysis page allows you to enter the parameter names and their associated step parameters. The dialog allows you to configure three different step modes:
To enter parameter step information, follow these steps:
Table Column | Description |
Parameter Name | The name of the stepped
parameter. The schematic symbols should be parameterized with this
parameter name using braced {} substitutions as shown at the top of the
dialog image above. Note: You can automatically change symbol property
values by using the Change testplan entry.
|
Step Type | The step type can be one of
the following:
|
Start Value | The starting value for the parameter step, used with decade and linear steps |
Stop Value | The ending value for the parameter step, used with decade and linear steps |
Number of Steps | The number of steps for the decade or linear steps. For decade steps, this parameter value is the number of steps per decade, for linear steps, the parameter value is the number of equally spaced steps. |
List Values | The list of stepped values. This cell is automatically populated by the dialog opened with the Define List... button. |
Additional parameters can be stepped by clicking on the Add... button and individual parameters can be removed with the Remove... button. The total number of steps is the product of number of steps for each stepped parameter. The total number of steps is calculated and shown below the table in the Total number of steps text.
Multi-core | |
Number of cores | The number of cores used for the simulation. The Pro and Elite licenses allow the use of 4 and 16 cores respectively. |
Save state | If checked, SIMPLIS will save initial conditions files with names which reflect the stepped parameter values. You can use the GenerateInitFile entry to save the initial conditions files and the IncludeInitFile entry to include these files. |
For more information on the multi-step analysis see the Advanced SIMPLIS Training topic: 3.1 Multi-Step Simulations.
The multi-step analysis has three configurations, each of which is entered in an Analysis column.
The Multi-Step analysis has the following syntax with the arguments described in the table below:
Analysis |
---|
Multi-Step |
Multi-Step( PARAM_NAME, STEP_TYPE, NUM_STEPS, START_VALUE, STOP_VALUE ) |
Multi-Step( PARAM_NAME, STEP_TYPE, NUM_STEPS, START_VALUE, STOP_VALUE, OPTIONAL_PARAMETER_STRING ) |
Argument | Range | Description |
PARAM_NAME | n/a | The name of the stepped parameter. The schematic symbols should be parameterized with this parameter name in braced {} substitutions. You can automatically change values using the Change testplan entry. |
STEP_TYPE |
|
The step
type can be one of the following:
|
NUM_STEPS | n/a | The number of steps for the decade or linear steps. |
START_VALUE | n/a | The starting value for the parameter step, used with decade and linear steps. |
STOP_VALUE | n/a | The ending value for the parameter step, used with decade and linear steps. |
OPTIONAL_PARAMETER_STRING | n/a | Two
additional parameter can be entered as a key=value pairs on the
OPTIONAL_PARAMETER_STRING. The two optional parameters are:
|
The LIST step type uses a variable length function call as described below. Every value after the PARAM_NAME and LIST arguments is interpreted as a parameter value to be stepped. The same OPTIONAL_PARAMETER_STRING options can be used with the LIST step type.
Analysis |
---|
Multi-Step( PARAM_NAME, LIST, VAL1, VAL2, VAL3, ..., VALN ) |
Multi-Step( PARAM_NAME, LIST, VAL1, VAL2, VAL3, ..., VALN , OPTIONAL_PARAMETER_STRING ) |
Where VAL1, VAL2, VAL3 ... VALN are the stepped parameter values.
Beginning with version 8.10, multiple parameter steps can be defined using the DVM Control Symbol dialog. To use the parameters defined in the DVM Control Symbol dialog, simply add an analysis column to an existing testplan and enter Multi-Step in the test row for this column. You can also define and step additional parameters using additional analysis columns. Each additional analysis column defines a new parameter step. Some examples will be helpful to understand how multiple analysis columns work.
In the DVM Control Dialog, two parameters, RLoad and Vin are defined with 5 and 3 stepped values respectively.
*** | ||||
---|---|---|---|---|
*** multi-step_power_assist.testplan | ||||
*** | ||||
*?@ Analysis | Analysis | Analysis | Objective | Label |
**** | ||||
Multi-Step | steady-state | Multi-Step|Uses Control Symbol Values | ||
Multi-Step | Multi-Step( L4_Tol, Linear, 3, 0.95, 1.05 ) | steady-state | Multi-Step|Control Symbol Steps Plus a Testplan Defined Step | |
Multi-Step( RLoad, List, 5, 4.2, 2.5 ) | Multi-Step( Vin, Linear, 3, 310, 330 ) | Multi-Step( L4_Tol, Linear, 3, 0.95, 1.05 ) | steady-state | Multi-Step|Testplan Defined |
There are cases where you may want to step a completely different set of parameter values from one test to another. One way to do this is to use multiple analysis columns in the testplan as is done with the last test in the above example. Another method is to change the DVM control symbol stepped parameter values on a test by test basis using a LoadComponentValues testplan entry. Each test uses a single analysis column with the basic Multi-Step testplan entry. Each test also has a LoadComponentValues entry placed prior (to the left of in the testplan) the analysis entry. The benefits to this method lay in consolidating all schematic changes in a single file. The built-in Efficiency testplan generator included in version 8.20 and newer uses this method. You can run the testplan generator using the menu.
*?@ LoadComponentValues | Analysis | Objective | Label |
---|---|---|---|
lcv\LTC3406B - DVM ADVANCED_efficiency_change.compvalues.txt | Multi-Step | Steady-State | Efficiency|Run Multi-Step Efficiency Simulation |
lcv\LTC3406B - DVM ADVANCED_efficiency_reset.compvalues.txt | NoSimulation | Efficiency|Generate Efficiency Curves |
1 | *** | ||
---|---|---|---|
2 | *** | ||
3 | *** | ||
4 | DVM_CONTROL.ANALYSIS_MULTI_STEP_PARAM_NAME | V2_VALUE;I1_VALUE | |
5 | DVM_CONTROL.ANALYSIS_MULTI_STEP_LIST_VALUES | 4.5,5,5.5;10,20,30,40,50,60,70,80,90,100 | |
6 | DVM_CONTROL.ANALYSIS_MULTI_STEP_NUM_CORES | 4 | |
7 | DVM_CONTROL.ANALYSIS_MULTI_STEP_STEP_TYPE | LIST;LIST | |
8 | *** | ||
9 | *** | ||
10 | V2.DC_VOLTAGE | {V2_VALUE} | |
11 | *** | ||
12 | I1.DC_CURRENT | {I1_VALUE*0.01*1.5} | |
13 | I1.LOAD_RESISTANCE | {1.505/(I1_VALUE*0.01*1.5)} |
1 | *** | ||
---|---|---|---|
2 | *** | ||
3 | *** | ||
4 | DVM_CONTROL.ANALYSIS_MULTI_STEP_PARAM_NAME | V2_VALUE;I1_VALUE | |
5 | DVM_CONTROL.ANALYSIS_MULTI_STEP_START_VALUE | 4.5;1 | |
6 | DVM_CONTROL.ANALYSIS_MULTI_STEP_STOP_VALUE | 5.5;10 | |
7 | DVM_CONTROL.ANALYSIS_MULTI_STEP_NUM_STEPS | 3;15 | |
8 | DVM_CONTROL.ANALYSIS_MULTI_STEP_STEP_TYPE | LIN;DEC |