[SOLVED] How to calculate fanout_latency for set_clock_gate_latency ?

[promach]

Could anyone advise how to calculate the values for -fanout_latency using the following examples ?


Example A

Example B

Example C

 

[promach]

Problem solved. See the following :


dc_shell> man set_clock_gate_latency



2. Synopsys Commands Command Reference
set_clock_gate_latency


NAME
set_clock_gate_latency
Specifies clock network latency values to be used for clock-gat-
ing cells, as a function of clock domain, clock-gating stage and
fanout.


SYNTAX
status set_clock_gate_latency
[-clock clock_list]
[-overwrite]
-stage cg_stage
-fanout_latency cg_fanout_list
[-transitive_fanout]


Data Types
clock_list list
cg_stage integer
cg_fanout_list string


ARGUMENTS
-clock clock_list
Specifies that the latency must be applied with respect to the
specified clocks. If the -clock option is not specified, the
latency is applied with respect to all clock domains to which
the clock-gating cell belongs.


-overwrite
Specifies that clock latency values previously set on clock-gat-
ing cells should be overwritten.


-stage cg_stage
Specifies the clock-gating stage to which the clock latency data
from the fanout range is applied. Registers are considered as
stage 0.


-fanout_latency cg_fanout_list
Specifies the list of clock-gating cells fanout and clock
latency values; for example, {1-5 0.9, 6-20 0.5, 21-inf 0.3}. A
fanout of 1 to 5 has a latency of 0.9; a fanout of 21 or larger
has a latency of 0.3. If the same latency value is wanted for
the entire fanout range, it can be specified as {1-inf 0.9}.


-transitive_fanout
Specifies that transitive fanout should be used instead of
direct fanout when annotating clock gate latency. Direct fanout
is the default.

 

[KlausST]

Hi,

Problem solved. See the following :

You may press the [Mark as Solved] button ;-)

Klaus