Am 24.04.19 um 02:35 schrieb Jython:
> yes, I need to do low power for stm32f4
> will this line work __asm__ volatile ("wfi");?That line should be correct. Please note that the instruction is already used in the armv7 idle thread: https://git.rtems.org/rtems/tree/cpukit/score/cpu/arm/armv7-thread-idle.c#n32 The stm32f4 is a Cortex-M4 so it's quite likely that this routine is used. You can check by doing an "arm-rtems5-objdump -dS" on your file and search for the idle body. With kind regards Christian > > > On Tue, Apr 23, 2019 at 10:28 PM Christian Mauderer > <christian.maude...@embedded-brains.de > <mailto:christian.maude...@embedded-brains.de>> wrote: > > Am 22.04.19 um 09:47 schrieb Jython: > > HI, ALL! > > wfi > http://www.keil.com/support/man/docs/armcc/armcc_chr1359125004400.htm > > how can i call the arm __wfi? > > > > _______________________________________________ > > users mailing list > > users@rtems.org <mailto:users@rtems.org> > > http://lists.rtems.org/mailman/listinfo/users > > > > Hello Jython, > > WFI is an assembler instruction. The Keil wrapper isn't available in > gcc. I know of no direct replacement. Most likely you need a gcc inline > assembly for that. > > May I ask why you would need "wfi"? If you use a operating system, the > system typically handles such low level stuff for you. The only > application that springs to mind for that instruction is overwriting the > idle loop to save energy. > > Best regards > > Christian > > -- > -------------------------------------------- > embedded brains GmbH > Herr Christian Mauderer > Dornierstr. 4 > D-82178 Puchheim > Germany > email: christian.maude...@embedded-brains.de > <mailto:christian.maude...@embedded-brains.de> > Phone: +49-89-18 94 741 - 18 > Fax: +49-89-18 94 741 - 08 > PGP: Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. > -- -------------------------------------------- embedded brains GmbH Herr Christian Mauderer Dornierstr. 4 D-82178 Puchheim Germany email: christian.maude...@embedded-brains.de Phone: +49-89-18 94 741 - 18 Fax: +49-89-18 94 741 - 08 PGP: Public key available on request. Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ users mailing list users@rtems.org http://lists.rtems.org/mailman/listinfo/users
