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9 years ago

still problems with timequest

Studying the AN 477 to page 15 I read:

At the FPGA (Receive) Side

example 4.# create a 125mhz clock# virtual_source: an ideal clock in the sourcing device# rx_clk: input clock port of the interface; 90 deg phase shifted

create_clock -name virtual_source -period 8

create_clock -name rx_clk -period 8 -waveform { 2 6 } [get_ports {rx_clk}]# set input delay based on the requirements mentioned previously# rx_clk is 90 deg phase shifted# input delay is relative to the rising and falling edges of the clock

set_input_delay -max 0.8 -clock [get_clocks virtual_source] -add_delay [get_ports rxd*]

set_input_delay -min -0.8 -clock [get_clocks virtual_source] -add_delay [get_ports rxd*]

set_input_delay -max 0.8 -clock_fall -clock [get_clocks virtual_source] -add_delay

[get_ports rxd*]

set_input_delay -min -0.8 -clock_fall -clock [get_clocks virtual_source] -add_delay

[get_ports rxd*]

set_input_delay -max 0.8 -clock [get_clocks virtual_source] -add_delay [get_ports

{rx_ctl}]

set_input_delay -min -0.8 -clock [get_clocks virtual_source] -add_delay [get_ports

{rx_ctl}]

set_input_delay -max 0.8 -clock_fall -clock [get_clocks virtual_source] -add_delay

[get_ports {rx_ctl}]

set_input_delay -min -0.8 -clock_fall -clock [get_clocks virtual_source] -add_delay

[get_ports {rx_ctl}]# set false paths to remove irrelevant setup and hold analysis

set_false_path -fall_from [get_clocks virtual_source] -rise_to [get_clocks {rx_clk}]

-setup

set_false_path -rise_from [get_clocks virtual_source] -fall_to [get_clocks {rx_clk}]

-setup

set_false_path -fall_from [get_clocks virtual_source] -fall_to [get_clocks {rx_clk}]

-hold

set_false_path -rise_from [get_clocks virtual_source] -rise_to [get_clocks {rx_clk}]

-hold

I use cyclonev dev board with marvell ethernet PHY.

I use the phy delay option for center align the rx data to rx clock (from phy to fpga).

I replaced the value 0.8 with the value 1.2 (see image).

But timequest analis fails hold slack.

where am I wrong?
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