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Altera_Forum's avatar
Altera_Forum
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16 years ago

How to constrain the JTAG in SOPC Builder

Hello everyone:

I have a DK-DSP-3C120N kit.Recently,I'm struggling with the DDR2 HP Controller under the direction of AN517(Using High-Performance DDR, DDR2, and DDR3 SDRAM With SOPC Builder).The design is targeted to the Cyclone® III EP3C120F780C7 Kit.

In this example,the SOPC system contain a Half-Rate DDR2 Controller working at 150MHz(altmemddr_auxfull),the PLL of the controller simultaneously generate a 75MHz output clock(altmemddr_sysclk) which been used as SOPC system clock.

After compilation,I got three critical warning,cause by JTAG.The TimeQuest report negative slack(-2.435) in Summary(Removal) of altera_reserved_tck.

The Top Failing Paths (Removal:altera_reserved_tck) is this:

Slack:-2.435

From---altera_reserved_tck

To-----pzdyqx:nabboc|pzdyqx_impl:zdyqx_impl_inst|FNUJ6967

I've tried to slow the DDR2 clock down to 133.333MHz,the NIOS clock down to 66.667MHz,but the slack value still negative.

I lose my head of this because I've constrained the JTAG using the templet:# JTAG Signal Constraints constrain the TCK port

create_clock -name tck -period 100.000 [get_ports altera_reserved_tck]# Cut all paths to and from tck

set_clock_groups -asynchronous -group [get_clocks altera_reserved_tck]# Constrain the TDI port

set_input_delay -clock altera_reserved_tck -clock_fall 1 [get_ports altera_reserved_tdi]# Constrain the TMS port

set_input_delay -clock altera_reserved_tck -clock_fall 1 [get_ports altera_reserved_tms]# Constrain the TDO port

set_output_delay -clock altera_reserved_tck -clock_fall 1 [get_ports altera_reserved_tdo]

I didn't know what's wrong with it.

Can anybody help me?

Thank you very much!

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    The error is not related to your DDR2 or NIOS clocks. You are obviously using an IP core in OpenCore Plus evaluation mode (because you don't have a license for it). All that is happening is there is a path failing on the JTAG clock domain with regards to the OpenCore evaluation mode.

    I would just ignore the error and move on with life.

    Jake