Re: libbsd zynqmp cpu freq for slcr calc
On 15/10/21 5:33 am, Kinsey Moore wrote: > On 10/14/2021 10:18, Joel Sherrill wrote: >> On Thu, Oct 14, 2021 at 9:56 AM Kinsey Moore >> wrote: >>> On 10/14/2021 01:40, Chris Johns wrote: Hi, I have come across this define in zynqmp_slcr.h: #define ZYNQMP_DEFAULT_PS_CLK_FREQUENCY What if the cpu freq is changed by a user? If this value still valid? >>> If CPU frequency scaling is used, I believe this value remains >>> unchanged. This is the base clock of the processing subsystem as a whole >>> which includes all hard peripherals. The CPU frequency is under the control system designer in these parts. >>> That's correct, this frequency could theoretically be changed by using >>> different parts on the board, different dividers somewhere, or probably >>> even forcing the PL to somehow generate the clock. This clock value has >>> been the same for all 3 ZynqMP boards I have on hand. >> If it can be changed by a user, should it be something that can be overridden >> by configuration? > > Yes, but it hasn't come up yet and so allowing for an override hasn't been a > priority. Agreed. I found after I had asked the question the zynq had the same value. > This might be one of those things that is best configured in RTEMS > since it's BSP-related configuration pertaining to a device, but would appear > to > be dead code/configuration since nothing there uses it. Yeap. At least it is noted now. Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: libbsd zynqmp cpu freq for slcr calc
On 10/14/2021 10:18, Joel Sherrill wrote: On Thu, Oct 14, 2021 at 9:56 AM Kinsey Moore wrote: On 10/14/2021 01:40, Chris Johns wrote: Hi, I have come across this define in zynqmp_slcr.h: #define ZYNQMP_DEFAULT_PS_CLK_FREQUENCY What if the cpu freq is changed by a user? If this value still valid? If CPU frequency scaling is used, I believe this value remains unchanged. This is the base clock of the processing subsystem as a whole which includes all hard peripherals. The CPU frequency is under the control system designer in these parts. That's correct, this frequency could theoretically be changed by using different parts on the board, different dividers somewhere, or probably even forcing the PL to somehow generate the clock. This clock value has been the same for all 3 ZynqMP boards I have on hand. If it can be changed by a user, should it be something that can be overridden by configuration? Yes, but it hasn't come up yet and so allowing for an override hasn't been a priority. This might be one of those things that is best configured in RTEMS since it's BSP-related configuration pertaining to a device, but would appear to be dead code/configuration since nothing there uses it. Kinsey ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: libbsd zynqmp cpu freq for slcr calc
On Thu, Oct 14, 2021 at 9:56 AM Kinsey Moore wrote: > > On 10/14/2021 01:40, Chris Johns wrote: > > Hi, > > > > I have come across this define in zynqmp_slcr.h: > > > > #define ZYNQMP_DEFAULT_PS_CLK_FREQUENCY > > > > What if the cpu freq is changed by a user? If this value still valid? > If CPU frequency scaling is used, I believe this value remains > unchanged. This is the base clock of the processing subsystem as a whole > which includes all hard peripherals. > > The CPU frequency is under the control system designer in these parts. > > That's correct, this frequency could theoretically be changed by using > different parts on the board, different dividers somewhere, or probably > even forcing the PL to somehow generate the clock. This clock value has > been the same for all 3 ZynqMP boards I have on hand. If it can be changed by a user, should it be something that can be overridden by configuration? --joel > > > Kinsey > > ___ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: libbsd zynqmp cpu freq for slcr calc
On 10/14/2021 01:40, Chris Johns wrote: Hi, I have come across this define in zynqmp_slcr.h: #define ZYNQMP_DEFAULT_PS_CLK_FREQUENCY What if the cpu freq is changed by a user? If this value still valid? If CPU frequency scaling is used, I believe this value remains unchanged. This is the base clock of the processing subsystem as a whole which includes all hard peripherals. The CPU frequency is under the control system designer in these parts. That's correct, this frequency could theoretically be changed by using different parts on the board, different dividers somewhere, or probably even forcing the PL to somehow generate the clock. This clock value has been the same for all 3 ZynqMP boards I have on hand. Kinsey ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
libbsd zynqmp cpu freq for slcr calc
Hi, I have come across this define in zynqmp_slcr.h: #define ZYNQMP_DEFAULT_PS_CLK_FREQUENCY What if the cpu freq is changed by a user? If this value still valid? The CPU frequency is under the control system designer in these parts. Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
