sleep time is doubled, xilinx_zynq_zedboard

[Giovanni Macciocu]

 Yes I've noticed the same thing. 

The ARM documentation states the following:

PERIPHCLK must be synchronous with CLK, and the PERIPHCLK clock period,
N, must be configured as a multiple of the CLK clock period. This
multiple N must be equal to, or greater than two.
(http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407f/CJHIGGDG.html)

So yes I think in this case the the multiple N = 2, resulting in a
peripheral bus clocked on half the speed. I would say this is a bug in
the xilinx_zynq_zedboard BSP,
the default value in configure.ac is 666666667U which can never be the
case as this is the CPU speed.

This still doens't solve the problem related to the serial port dough.
I've rolled back to an rtems head of +/- half a year ago. There my
serial port does work with a baudrate at 11500, i haven't been able to
tacke the difference.

Regards,

Giovanni
 
>>> Thomas Doerfler <Thomas.Doerfler at embedded-brains.de> 5/1/2014 2:38
PM >>> 
Giovanni,

without knowing the BSP: You are talking about CPU clock, the macro is
call Periphclk. Can it be that the peripheral bus is clocked with half
of the CPU frequency?

wkr,

Thomas.

Am 01.05.2014 12:52, schrieb Giovanni Macciocu:
> I've made some tests by changing the value of 
BSP_ARM_A9MPCORE_PERIPHCLK.
> The value should be 666666667U as this is my cpu clock speed. 
> 
> However in the following cases
> 
> #define BSP_ARM_A9MPCORE_PERIPHCLK (2 * 666666667U)
> 
> --> a Sleep now takes 4 times as long
> 
> #define BSP_ARM_A9MPCORE_PERIPHCLK 2 (666666667U / 2)
> 
> --> The sleep is now correct
> 
> In all cases the serial port keeps working at half of the normal
buadrate.
> 
> Regards,
> 
> Giovanni
> 
>  
>>>> "Giovanni Macciocu" <G.Macciocu at sron.nl> 5/1/2014 10:53 AM >>> 
> In my bspopt.h
> 
> /* ARM Cortex-A9 MPCore PERIPHCLK clock frequency in Hz */
> #define BSP_ARM_A9MPCORE_PERIPHCLK 666666667U
> 
> This is the correct processor speed for my platform.
>  
>>>> Chris Johns <chrisj at rtems.org> 5/1/2014 10:24 AM >>> 
> t you take a look at the BSPOPTS for the zync BSP. There are 
> some clocks you can set and one of these may help. I think 
> BSP_ARM_A9MPCORE_PERIPHCLK is the one.
> 
> Chris
> 
> 
> 
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