UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

Reply

JESD CDC failures

Highlighted
Explorer
Posts: 144
Registered: ‎07-29-2009

JESD CDC failures

[ Edited ]

I am using the JESD core and run the CDC Report. I found that there are a few related to the JESD:

 

  1. Critical CDC-10 Combinatorial logic detected before a synchronizer 7 False Path reference_emitter_i/jesd204_0/inst/i_jesd204_phy/inst/jesd204_phy_block_i/reference_emitter_jesd204_0_0_phy_gt/inst/reference_emitter_jesd204_0_0_phy_gt_i/gt0_reference_emitter_jesd204_0_0_phy_gt_i/gtxe2_i/TXUSRCLK2 reference_emitter_i/jesd204_0/inst/i_jesd204_phy/inst/jesd204_phy_block_i/reference_emitter_jesd204_0_0_phy_gt/inst/gt_txresetfsm_i/sync_TXRESETDONE/data_sync_reg1/D Unsafe
  2. Critical CDC-12 Multi-clock fan-in to synchronizer 5 False Path reference_emitter_i/jesd204_0/inst/jesd204_block_i/i_reference_emitter_jesd204_0_0/i_tx/i_tx_counters_32/got_sysref_r_reg/C reference_emitter_i/jesd204_0/inst/jesd204_block_i/sync_tx_sysref_captured/syncstages_ff_reg[0]/D Unsafe
  3. Critical CDC-10 Combinatorial logic detected before a synchronizer 2 Max Delay Datapath Only CLK_IN_SYSREF_clk_p[0] reference_emitter_i/jesd204_0/inst/jesd204_block_i/tx_sysref_r_reg/D Unsafe
  4. Critical CDC-10 Combinatorial logic detected before a synchronizer 2 Max Delay Datapath Only CLK_IN_SYSREF_clk_p[0] reference_emitter_i/jesd204_0/inst/jesd204_block_i/tx_sysref_r_reg/D No ASYNC_REG

I've added the constraints the documentation seems to indicate to my TCL script:

set_false_path -from [get_cells -hier -filter {name =~ *jesd204_block_i/tx_cfg* && IS_SEQUENTIAL}]
set_false_path -from [get_cells -hier -filter {name =~ *jesd204_block_i/tx_sysref_delay_reg* && IS_SEQUENTIAL}]

set_multicycle_path -setup 3  -from [get_cells -hier -filter {name =~ *jesd204_block_i/i_axi_lite_ipif/I_SLAVE_ATTACHMENT/bus2ip_addr_reg_reg* && IS_SEQUENTIAL}] -to [get_cells -hier -filter {name =~ *IP2Bus_Data_reg* && IS_SEQUENTIAL}]
set_multicycle_path -hold 2  -from [get_cells -hier -filter {name =~ *jesd204_block_i/i_axi_lite_ipif/I_SLAVE_ATTACHMENT/bus2ip_addr_reg_reg* && IS_SEQUENTIAL}] -to [get_cells -hier -filter {name =~ *IP2Bus_Data_reg* && IS_SEQUENTIAL}]
set_multicycle_path -setup 3  -from [get_cells -hier -filter {name =~ *jesd204_block_i/i_axi_lite_ipif/I_SLAVE_ATTACHMENT/GEN_USE_WSTRB.bus2ip_be_reg_reg* && IS_SEQUENTIAL}] -to [get_cells -hier -filter {name =~ *IP2Bus_Data_reg* && IS_SEQUENTIAL}]
set_multicycle_path -hold 2  -from [get_cells -hier -filter {name =~ *jesd204_block_i/i_axi_lite_ipif/I_SLAVE_ATTACHMENT/GEN_USE_WSTRB.bus2ip_be_reg_reg* && IS_SEQUENTIAL}] -to [get_cells -hier -filter {name =~ *IP2Bus_Data_reg* && IS_SEQUENTIAL}]
set_multicycle_path -setup 3  -from [get_cells -hier -filter {name =~ *jesd204_block_i/i_axi_lite_ipif/I_SLAVE_ATTACHMENT/I_DECODER/GEN_BKEND_CE_REGISTERS[0].rdce_out_i_reg[0] && IS_SEQUENTIAL}] -to [get_cells -hier -filter {name =~ *IP2Bus_Data_reg* && IS_SEQUENTIAL}]
set_multicycle_path -hold 2  -from [get_cells -hier -filter {name =~ *jesd204_block_i/i_axi_lite_ipif/I_SLAVE_ATTACHMENT/I_DECODER/GEN_BKEND_CE_REGISTERS[0].rdce_out_i_reg[0] && IS_SEQUENTIAL}] -to [get_cells -hier -filter {name =~ *IP2Bus_Data_reg* && IS_SEQUENTIAL}]

 

Is there something I'm missing?

Regards,

Kurt

Moderator
Posts: 3,204
Registered: ‎02-06-2013

Re: JESD CDC failures

Hi

 

Which version of the core are you using?

 

Have you tried with the example design in 2017.2 and still see the CDC reported?

Regards,

Satish

--------------------------------------------------​--------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.

Give Kudos to a post which you think is helpful.
--------------------------------------------------​-------------------------------------------
Explorer
Posts: 144
Registered: ‎07-29-2009

Re: JESD CDC failures

I'm using 2016.4 Ver 7.1 (Rev 1). No, I didn't know to synthesize the example design. Nevertheless, are you able to see those signals and how they're constrained? I am applying what I think was required by reading the documentation.

Moderator
Posts: 3,204
Registered: ‎02-06-2013

Re: JESD CDC failures

Hi

 

Attach your xci file of the core to check with example design at my end.

Regards,

Satish

--------------------------------------------------​--------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.

Give Kudos to a post which you think is helpful.
--------------------------------------------------​-------------------------------------------
Explorer
Posts: 144
Registered: ‎07-29-2009

Re: JESD CDC failures

Do you want the XCI of the JESD core, or of my total project?  I'm uploading the JESD core: the PHY and the main.
Kurt