dni::set_clock_latency (::quartus::dni

Tcl Package and Version

Syntax

dni::set_clock_latency [-h | -help] [-long_help] [-clock <clock_list> ] [-dynamic <jitter> ] [-early] [-fall] [-late] [-max] [-min] [-rise] -source <delay> <targets>

Arguments

-h | -help

Short help

-long_help

Long help with examples and possible return values

-clock <clock_list>

Valid clock destinations (string patterns are matched using Tcl string matching)

-dynamic <jitter>

Specifies the dynamic component of the clock latency, which represents the amount of jitter in the original clock source

-early

Specifies the early clock latency

-fall

Specifies the falling transition clock latency

-late

Specifies the late clock latency

-max

Specifies the clock latency at the worst-case operation condition

-min

Specifies the clock latency at the best-case operation condition

-rise

Specifies the rising transition clock latency

-source

Specifies the source clock latency

<delay>

Latency delay value

<targets>

Valid destinations (string patterns are matched using Tcl string matching)

Description

Specifies clock latency for a given clock or clock target.

There are two types of latency: network and source. Network latency is
the clock network delay between the clock and register clock pins.
Source latency is the clock network delay between the clock and its
source (e.g., the system clock or base clock of a generated clock).

The Timing Analyzer automatically computes network latencies for all
register and generated clocks. Overriding clock network latencies is
not supported by the Timing Analyzer. Therefore, the -source option
must always be specified.

You can apply clock latency to a clock, which affects all targets of
the clock, or to a specific clock target. If you specify a specific
clock target that is driven by more than one clock, use the -clock
option to specify which clock to use.Latencies assigned to a clock
target override any latencies assigned to a clock.

Different clock latencies can be specified for early (-early) and late
(-late) latencies, as well as for rising edges (-rise) and falling
edges (-fall). If only some combinations are specified, the other
combinations are used by default. For example, if only a -rise -early
latency and a -fall -early latency are specified, then the -rise -late
latency is assumed to be the same as the -rise -early latency and the
-fall -late latency is assumed to be the same as the -fall -early
latency. If neither -rise nor -fall are used or neither -early nor
-late are used, then the latency applies to both conditions.

Source latency can also be assigned to generated clocks. This may be
useful for specifying board level delays from a clock output port to a
clock input port when the clock input port is acting as a feedback
clock.

The value of the targets is either a collection or a Tcl list of
wildcards used to create a collection of the appropriate type.

Note -dynamic is not supported yet.

Example Usage

create_clock -name SYSCLK -period 10.000 [get_ports inclk]
create_generated_clock -name OUTCLK -divide_by 1 -source [get_ports inclk] [get_ports outclk]
create_generated_clock -name FDBKCLK -divide_by 1 -source [get_ports outclk] [get_ports fdbkclk]

# Apply a simple 2.000 ns source latency to the system clock.
set_clock_latency -source 2.000 [get_clocks SYSCLK]

# Specify feedback clock latencies between output port outclk
# and the input port fdbkclk.
set_clock_latency -source -late -rise 0.800 [get_clocks FDBKCLK]
set_clock_latency -source -late -fall 0.750 [get_clocks FDBKCLK]
set_clock_latency -source -early -rise 0.500 [get_clocks FDBKCLK]
set_clock_latency -source -early -fall 0.460 [get_clocks FDBKCLK]

Return Value

Code Name

Code

String Return

TCL_OK

0

INFO: Operation successful

Tcl Package and Version	Belongs to ::quartus::dni_sdc 1.5
Syntax	`dni::set_clock_latency [-h \| -help] [-long_help]` `[-clock` <clock_list> `]` `[-dynamic` <jitter> `]` `[-early]` `[-fall]` `[-late]` `[-max]` `[-min]` `[-rise]` `-source` <delay> <targets>
Arguments	`-h \| -help`		Short help
	`-long_help`		Long help with examples and possible return values
	`-clock` <clock_list>		Valid clock destinations (string patterns are matched using Tcl string matching)
	`-dynamic` <jitter>		Specifies the dynamic component of the clock latency, which represents the amount of jitter in the original clock source
	`-early`		Specifies the early clock latency
	`-fall`		Specifies the falling transition clock latency
	`-late`		Specifies the late clock latency
	`-max`		Specifies the clock latency at the worst-case operation condition
	`-min`		Specifies the clock latency at the best-case operation condition
	`-rise`		Specifies the rising transition clock latency
	`-source`		Specifies the source clock latency
	<delay>		Latency delay value
	<targets>		Valid destinations (string patterns are matched using Tcl string matching)
Description	Specifies clock latency for a given clock or clock target. There are two types of latency: network and source. Network latency is the clock network delay between the clock and register clock pins. Source latency is the clock network delay between the clock and its source (e.g., the system clock or base clock of a generated clock). The Timing Analyzer automatically computes network latencies for all register and generated clocks. Overriding clock network latencies is not supported by the Timing Analyzer. Therefore, the -source option must always be specified. You can apply clock latency to a clock, which affects all targets of the clock, or to a specific clock target. If you specify a specific clock target that is driven by more than one clock, use the -clock option to specify which clock to use.Latencies assigned to a clock target override any latencies assigned to a clock. Different clock latencies can be specified for early (-early) and late (-late) latencies, as well as for rising edges (-rise) and falling edges (-fall). If only some combinations are specified, the other combinations are used by default. For example, if only a -rise -early latency and a -fall -early latency are specified, then the -rise -late latency is assumed to be the same as the -rise -early latency and the -fall -late latency is assumed to be the same as the -fall -early latency. If neither -rise nor -fall are used or neither -early nor -late are used, then the latency applies to both conditions. Source latency can also be assigned to generated clocks. This may be useful for specifying board level delays from a clock output port to a clock input port when the clock input port is acting as a feedback clock. The value of the targets is either a collection or a Tcl list of wildcards used to create a collection of the appropriate type. Note -dynamic is not supported yet.
Example Usage	create_clock -name SYSCLK -period 10.000 [get_ports inclk] create_generated_clock -name OUTCLK -divide_by 1 -source [get_ports inclk] [get_ports outclk] create_generated_clock -name FDBKCLK -divide_by 1 -source [get_ports outclk] [get_ports fdbkclk] # Apply a simple 2.000 ns source latency to the system clock. set_clock_latency -source 2.000 [get_clocks SYSCLK] # Specify feedback clock latencies between output port outclk # and the input port fdbkclk. set_clock_latency -source -late -rise 0.800 [get_clocks FDBKCLK] set_clock_latency -source -late -fall 0.750 [get_clocks FDBKCLK] set_clock_latency -source -early -rise 0.500 [get_clocks FDBKCLK] set_clock_latency -source -early -fall 0.460 [get_clocks FDBKCLK]
Return Value	Code Name	Code	String Return
TCL_OK	0	INFO: Operation successful

dni::set_clock_latency (::quartus::dni_sdc)