An illegal LCB was detected.

[matferronato]

Hi,

I created 4 partitions in my design, ran synthesis and place & route, and exported the final qdb.

Then when I tried to reload the design and source the respective partition database, I get the error

An illegal LCB was detected.

Error:
Internal Error: Sub-system: LAB, File: /quartus/legality/lab/lab_fm_40_config_creator_module.cpp, Line: 1570
LCB SOLVER COULD NOT FIND A SOLUTION. CHECK DEBUG
An illegal LCB was detected.
A modification to the atom netlist that was not legalized was made in Stage: Place
Save any *json and *dot files generated at the time of this IE. Check debug output for next steps.
Stack Trace:
Quartus 0x23189: LAB_CONFIG_CREATOR_MODULE_FALCONMESA_40::populate_config_nonempty(LAB_CONFIG_FALCONMESA_40*, CDB_CHIP_DB_ENTRY_WRAPPER*, DBCM_DEVICE const*) [clone .cold] + 0x531 (legality_lab)
Quartus 0xf5aab: U2B2_MODULE::populate_config(U2B2_CONFIG*, CDB_CHIP_DB_ENTRY_WRAPPER*, DBCM_DEVICE const*) + 0x4f (db_u2b2_core)
Quartus 0xc237c: U2B2_DIRECTOR::populate_configs_fn(U2B2_MODULE*, U2B2_CONTEXT const&, U2B2_CONFIG*) const + 0x92 (db_u2b2_core)
Quartus 0xcf190: tbb::detail::d2::for_each_iteration_task<tbb::detail::d2::hash_map_iterator<tbb::detail::d2::concurrent_hash_map<QSYM, U2B2_CONFIG*, QTL_TBB_OPS<QSYM>, tbb::detail::d1::tbb_allocator<std::pair<QSYM const, U2B2_CONFIG*> > >, std::pair<QSYM const, U2B2_CONFIG*> const>, U2B2_DIRECTOR::populate_configs(U2B2_CONTEXT const&) const::{lambda(std::pair<QSYM const, U2B2_CONFIG*>)#1}, std::pair<QSYM const, U2B2_CONFIG*> const>::execute(tbb::detail::d1::execution_data&) + 0x156 (db_u2b2_core)
Quartus 0x161d3: tbb::detail::r1::task_dispatcher::execute_and_wait(tbb::detail::d1::task*, tbb::detail::d1::wait_context&, tbb::detail::d1::task_group_context&) + 0x763 (tbb)
Quartus 0xc1a5a: tbb::detail::d2::forward_block_handling_task<tbb::detail::d2::hash_map_iterator<tbb::detail::d2::concurrent_hash_map<QSYM, U2B2_CONFIG*, QTL_TBB_OPS<QSYM>, tbb::detail::d1::tbb_allocator<std::pair<QSYM const, U2B2_CONFIG*> > >, std::pair<QSYM const, U2B2_CONFIG*> const>, U2B2_DIRECTOR::populate_configs(U2B2_CONTEXT const&) const::{lambda(std::pair<QSYM const, U2B2_CONFIG*>)#1}, std::pair<QSYM const, U2B2_CONFIG*> const>::execute(tbb::detail::d1::execution_data&) + 0x8a (db_u2b2_core)
Quartus 0x24203: tbb::detail::r1::market::process(rml::job&) + 0xad3 (tbb)
Quartus 0x1f562: tbb::detail::r1::rml::private_worker::thread_routine(void*) + 0x52 (tbb)
System 0x8609: start_thread + 0xd9 (pthread)
System 0x11f353: clone + 0x43 (c)

System Information
Platform: linux64
OS name: Ubuntu 20.04.5
OS version: 20

I see this issue described in

https://www.intel.com/content/www/us/en/support/programmable/articles/000090729.html?countrylabel=Asia%20Pacific

But it was supposed to be fixed in quartus 22, and I'm currently using quartus 23

Any idea on how to tackle this issue?

[SyafieqS]

Are you using Agilex edition? What device are you using?

[matferronato]

I'm currently using Agilex AGFB014R24B2E2V

[SyafieqS]

Perhaps do you mid to share the design to me to replicate this?

[matferronato]

 Unfortunately i cannot share the design.

What would be a good way to start debuging this issue?

What does An illegal LCB means?

[SyafieqS]

Most of the time internal error is related to tool issue (although there are cases it is not).

We need the design to root cause and provide workaround if possible otherwise it will be hard.

If you cant provide the design, a small test case that replicate the issue will be enough.

[RichardTanSY_Intel]

Hi,

Do you able to share a simplified design that to duplicate the error?

If the design cannot be shared publicly, please let me know, and I'll send you an email to facilitate the transfer of files through FTP(Files Transfer Protocol).

Regards,

Richard Tan

[SyafieqS]

As we do not receive any response from you on the previous question/reply/answer that we have provided. Please login to https://supporttickets.intel.com/, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you on your follow-up questions.

p/s: If any answer from community or Intel support are helpful, please feel free to mark as solution, give Kudos and rate 5/5 survey