Clock Latency
Syntax: Clock latency specifies the amount of delay for a clock signal reaching to the clock pin of a sequential element from the clock source pin.
There are two types of clock latency one is network latency (default) and the other is source latency (by using the -source option) Example: set_clock_latency 2.35 [get_pins ABC/XYZ/CP]
Clock Uncertainty
Syntax: After defining the clock, to take care of variance in the clock network clock uncertainty added.
Clock uncertainty adds some margin of error into the system to account for variance in the clock network caused by non-ideality of clock network and clock source itself.Above specified command can specify either inter-clock uncertainty or simple.
Create Generated Clock
Syntax: create_generated_clock [-name clock_name] [-add] source_objects -source master_pin [-master_clock clock] [-divide_by divide_factor | -multiply_by multiply_factor ] [-duty_cycle percent] [-invert] [-preinvert] [-edges edge_list] [-edge_shift edge_shift_list] [-combinational] The create_generated_clock command creates a generated clock object.
Does design compiler NXT detect SDC errors?
Correct synthesis results depend on accurate SDCs.
Design Compiler NXT can detect some types of SDC errors, such as:
referencing signals and modules not in the design.
But a specification error such as:specifying that figure 1 contains a four-cycle path will result in a design that does not work as intended. Group Path
Syntax: Groups are a set of paths or endpoints for the cost function calculations.
The group enables us to specify a set of paths to optimize even though there may be a larger violation in other groups.
When endpoints have been specified all paths leading to those end paths are grouped.
Example: group_path -name “group1” -weight 2.0 -to {CLK1A CLK1.
How do I use set_false_path?
You can use the set_false_path command to specify your design's false paths (i.e., paths that can be ignored during timing analysis).
The following list shows the available options for the set_false_path command:
set_false_path [-from ] [-to ] [-thru ] Table 1 Describes the options for the set_false_path command. Why is set_clock_groups better than set_false_path?
The advantage of set_clock_groups is simple.
It saves us from defining too many false paths.
That's why 2a is better than 1b.
If we have more clocks, it will help much more.
Note that set_false_path has the highest precedence in SDC files, so it trumps all other constraints.
Syllable repertoire of B5900, B6500, B7500 and successors
The Burroughs B6x00-7x00 instruction set includes the set of valid operations for the Burroughs B6500,
B7500 and later Burroughs large systems, including the current Unisys Clearpath/MCP systems; it does not include the instruction for other Burroughs large systems including the B5000, B5500, B5700 and the B8500.
These unique machines have a distinctive design and instruction set.
Each word of data is associated with a type, and the effect of an operation on that word can depend on the type.
Further, the machines are stack based to the point that they had no user-addressable registers.
