Device Family: Intel® Stratix® 10

Intel Software: Quartus Prime Pro

Type: Answers

Area: HSIO


Version Found: v19.4
Bug ID: 22010730498

Why do I see hold-time violations when using more than one instance of an Intel® Stratix® 10 E-tile device transceiver IP? 

Description

You may see hold-time violations caused by uncut false paths when using more than one instance of an Intel Stratix 10 E-tile device transceiver IP.

The hold-time violations involve AIB registers clocked from two independent transceiver IP instances. The IP’s should apply false paths between multiple channels within an IP, but you must apply false path SDC constraints between multiple transceiver IP.

Workaround/Fix

To work around this problem, you can apply set_false_path constraints in your top level SDC file.

The example below demonstrates how you can apply a false path between two nodes of unrelated transceiver IP

Ignore Path:

set aib_tx_internal_div_reg_col [get_registers -nowarn nphy_instance_1.xcvr_client_inst|xcvr_native_s10_etile_0|g_xcvr_native_insts[0].ct3_xcvr_native_inst|inst_ct3_xcvr_channel|inst_ct1_hssi_pldadapt_tx~aib_tx_internal_div.reg]

set aib_fabric_transfer_clk_col [get_registers -nowarn nphy_instance_2.xcvr_client_inst|xcvr_native_s10_etile_0|g_xcvr_native_insts[0].ct3_xcvr_native_inst|inst_ct3_xcvr_channel|inst_ct1_hssi_pldadapt_tx~s2_6_0__aibadpt__aib_fabric_tx_transfer_clk.reg]

Next Step: Set False Path

set_false_path -from aib_tx_internal_div_reg_col -to aib_fabric_transfer_clk_col