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NIOS usleep simulation

Altera_Forum
Honored Contributor II
‎07-30-2009 08:22 AM
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Hello! 

 

I am new to NIOS, and I'm trying to simulate a NIOS2 based design using ModelSim. 

 

Everything runs as expected (accesses to Avalon slaves, printf thru Jtag-Uart, ...), except for "usleep" instructions. 

 

"usleep" calls compile with no warnings (IDE), execute with no errors (Modelsim), but the simulator shows the same duration regardless of the argument given (1us, 100us, 100000us). 

 

Any hints? 

 

Jean-Christophe
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Altera_Forum
Honored Contributor II
‎07-30-2009 09:02 AM
431 Views

Ahaha! 

I found the answer myself, after investigating for half a day... 

 

The function that implements the actual sleep is "alt_busy_sleep()". 

This function checks wether "ALT_SIM_OPTIMIZE" is defined to decide if it skips wait cycles (simulation) or pauses for a while (real target). 

 

Sorry for bothering you all :-)
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