Rough evaluation of execution time

Fabio Degiovanni - Eicas degiovanni at
Tue Sep 16 09:33:08 UTC 2003

Dear Thomas Doerfler,
                                    Thank you very much, I was searching 
about these confirmations. What you wrote about the simulator was what I 
thought but I needed a confirmation becuase I'm new of ERC32 and ERC32 
Thank you very much

Fabio Degiovanni

Thomas Doerfler wrote:

>Hello Fabio,
>I am not a ERC32 specialist, but I had a short look at the 
>simulator. I found out two thing:
>If I simply enter 
>$ sparc-rtems-sis --help
>I get the following output:
>zerberus:/home/thomas # /opt/rtems/bin/sparc-rtems-sis --help
> SIS - SPARC intruction simulator 2.7.5,  copyright Jiri Gaisler 1995
> Bug-reports to jgais at
>unknown option --help
>usage: sis [-uart1 uart_device1] [-uart2 uart_device2]
>[-nfp] [-freq frequency] [-c batch_file] [files]
>[-sparclite] [-dumbio]
>I would assume that you can specify the system frequency that 
>you want to simulate with option "-freq"
>If I start the simulator, and enter the "perf" command, I get 
>the following line in output:
> ERC32 performance (14.0 MHz):   nan MOPS (  nan MIPS,   nan 
>so I would assume, that the ERC32 is simulated by default with 
>a 14 MHz clock. Does this make sense?
>I general, good simulators will simulate the behaviour of the 
>chip on a system clock per clock basis. So the events ocurring 
>in the simulated chip really do not depend on the speed of the 
>host computer, that simulates the chip. Assuming a 14MHz 
>clock, the RTEMS time-of-day should be incremented by one 
>second, when 14 million clock cycles have been simulated. I 
>treally doesn't matter in this situation, whether your host 
>computer has taken 100 Milliseconds or 10 Minutes to simulate 
>these 14 Million clock events. 
>Does this help you a bit?
>	Thomas.
>>Dear Sirs,
>>	In the last days I sent some questions about a rough evaluation of 
>>execution time using gdb/sis simulator of ERC32. Some of my questions 
>>didn't find an answer. I kindly ask anyone of you that could help me to 
>>reply this message when you find time.
>>Could anyone told me where I can find what erc32 is simulated by sis/gdb
>>(a 10, 14, or 15 Mhz or what)?
>>Joel Sherrill told me that the simulator's notion of
>>time is independent of the host computer's
>>speed. What about the time resolution? I presume that this is host
>>computer dipendent. In which way? When I use the 
>>CONFIGURE_MICROSECONDS_PER_TICK for configuring time resolution in RTEMS 
>>do I affect the time resolution of the simulator or is it host computer 
>>Thank you very much for help
>>Fabio Degiovanni
>>Dott. Ing. Degiovanni Fabio
>>Eicas Automazione
>>Via Vincenzo Vela, 27 10128 Torino (ITALIA)
>>Telefoni +39-11-562.37.98/562.3088 Fax +39-11-436.06.79
>IMD Ingenieurbuero fuer Microcomputertechnik
>Thomas Doerfler           Herbststrasse 8
>D-82178 Puchheim          Germany
>email:    Thomas.Doerfler at
>PGP public key available at: http://www.imd-

Dott. Ing. Degiovanni Fabio
Eicas Automazione
Via Vincenzo Vela, 27 10128 Torino (ITALIA)
Telefoni +39-11-562.37.98/562.3088 Fax +39-11-436.06.79

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