Possible solultion but not tested yet:
void hal_delay_us(cyg_int32 usecs)
{
cyg_int64 ticks;
cyg_uint32 val1, val2;
cyg_uint32 piv;
// Calculate how many PIT ticks the required number of microseconds
// equate to. We do this calculation in 64 bit arithmetic to avoid
// overflow.
ticks = (((cyg_uint64)usecs) *
((cyg_uint64)CYGNUM_HAL_ARM_AT91_CLOCK_SPEED))/16/1000000LL;
HAL_READ_UINT32(AT91_PITC + AT91_PITC_PIMR, piv);
piv = (piv & 0xffffff) -1; //periode
hal_clock_read(&val1);
while (ticks > 0) {
hal_clock_read(&val2);
if (val2 < val1)
ticks -= ((piv + val2) - val1); //overflow occurred
else
ticks -= (val2 - val1);
val1 = val2;
}
}
Oliver Munz
----- Original Message -----
From: "Andrew Lunn" <[EMAIL PROTECTED]>
To: "oliver munz @ s p e a g" <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Thursday, March 23, 2006 9:03 PM
Subject: Re: Initialisation for the AT91... PIT if there is no kernel...
On Tue, Mar 21, 2006 at 11:49:38PM +0100, oliver munz @ s p e a g wrote:
This Patch fixes problems whit the AT91 PIT, if it should run whitout the
kernel.
This fixes the problem a different way.
Andrew
