$sdf_annotate中scale_type的FROM_MTM是什么

yiliang79

最近在做后仿，反标时会有scale_type，其中default是FROM_MTM,请问各位大佬这个MTM是什么意思，vcs2023user guide中并没有进行解释，max和min和typical都好理解，MTM实在不理解是什么意思，有没有大佬懂的，非常感谢！

下面贴上Verification Continuum™ VCS User Guide V-2023.12 page644中对于该项的描述：

Using the $sdf_annotate System Task
You can use the $sdf_annotate system task to back-annotate delay values from an SDF
file to your Verilog design.
The syntax for the $sdf_annotate system task is as follows:
$sdf_annotate ("sdf_file"[, module_instance]
[,"sdf_configfile"][,"sdf_logfile"][,"mtm_spec"]
[,"scale_factors"][,"scale_type"]);

......

"scale_type"
Specifies the delay value from each triplet in the SDF file for use before scaling.
Its possible values are "FROM_TYPICAL", "FROM_MIMINUM", "FROM_MAXIMUM", and
"FROM_MTM" (default).

yiliang79

再附上关于MTM的其他描述，似乎意思是可以指定FROM_MTM，然后在simv option里面指定为max/min/typical？

The MTM Command
The command annotates the minimum, typical, or maximum delay value. You can specify
one of the following keywords:
MINIMUM Annotates the minimum delay value.
TYPICAL Annotates the typical delay value.
MAXIMUM Annotates the maximum delay value.
TOOL_CONTROL Delay value is determined by the command-line options of the Verilog tool
(+mindelays, +typdelays, or +maxdelays).
The default for the MTM command is TOOL_CONTROL and its syntax is as follows:
MTM = MINIMUM | TYPICAL | MAXIMUM | TOOL_CONTROL;

......

For example:
MTM=MAXIMUM;
The SCALE Commands
There are the following two types of SCALE commands:
• SCALE_FACTORS - Set of three real number multipliers that scale the timing information
in the SDF file to the minimum, typical, and maximum timing information that is backannotated to the Verilog tool. Each multiplier represents a positive real number, for
example 1.6:1.4:1.2.
• SCALE_TYPE - Selects one of the following keywords to scale the timing specification in
the SDF file to the minimum, typical, and maximum timing that is back-annotated to the
Verilog tool.
FROM_MINIMUM Scales from the minimum timing specification in the SDF file.
FROM_TYPICAL Scales from the typical timing specification in the SDF file.
FROM_MAXIMUM Scales from the maximum timing specification in the SDF file.
FROM_MTM Scales directly from the minimum, typical, and maximum timing specifications in
the SDF file.
.
The syntax of SCALE_FACTORS and SCALE_TYPE is as follows:
SCALE_FACTORS = number : number : number;
SCALE_TYPE = FROM_MINIMUM | FROM_TYPICAL | FROM_MAXIMUM | FROM_MTM;
For example:
SCALE_FACTORS=100:0:9;
SCALE_TYPE=FROM_MTM;
SCALE_FACTORS=1.1:2.1:3.1;
SCALE_TYPE=FROM_MINIMUM;

sfc19910705

跟你的理解差不多，delay调用反标函数的时候指定，或者通过仿真编译选项指定