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sidney 2024-12-31 18:11:35 +01:00
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doc/sim65.sgml
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@ -276,13 +276,12 @@ Jan 1st, 1970 UTC, at the time of the last latch operation. The low 32 bits of
<p>The two different wallclock-time latch registers will always refer to precisely the same time instant.
For some applications, the single 64-bit value measured in nanoseconds will be more convenient, while
for other applications, the split 32/32 bits representations with separate seconds and nanosecond
for other applications, the split 32/32 bits representations with separate second and nanosecond
values will be more convenient.
<p>Note that the definition above, with time elapsed measured since Midnight, Jan 1st, 1970 UTC is
an approximation, as the implementation depends on the way POSIX definition time, which does
not account for leap seconds (POSIX falsely assumes that all days are precisely 86400 seconds
long).
<p>Note that the definition above, with time elapsed measured since Midnight, Jan 1st, 1970 UTC, is
an approximation, as the implementation depends on the way POSIX definition time, and POSIX does
not account for leap seconds; it falsely assumes that all days are precisely 86400 seconds long.
<p>On reset, <tt>PERIPHERALS_COUNTER_SELECT</tt> is initialized to zero. If the <tt>PERIPHERALS_COUNTER_SELECT</tt>
register holds a value other than one of the six values described above, all <tt>PERIPHERALS_COUNTER_VALUE</tt>
@ -295,6 +294,39 @@ while address $FFC9 holds the most significant byte (MSB).
<p>On reset, all latch registers are reset to zero. Reading any of the <tt>PERIPHERALS_COUNTER_VALUE</tt>
bytes before the first write to <tt>PERIPHERALS_COUNTER_LATCH</tt> will yield zero.
Example:
<tscreen><verb>
#include <stdio.h>
#include <stdint.h>
volatile uint8_t * CounterLatch = (uint8_t *)0xffc0;
volatile uint8_t * CounterSelect = (uint8_t *)0xffc1;
volatile uint32_t * CounterValue = (uint32_t *)0xffc1;
static void print_current_counters(void)
{
*CounterLatch = 0; /* latch values */
*CounterSelect = 0x00;
printf("clock cycles ............... : %08lx %08lx\n", CounterValue[1], CounterValue[0]);
*CounterSelect = 0x01;
printf("instructions ............... : %08lx %08lx\n", CounterValue[1], CounterValue[0]);
*CounterSelect = 0x80;
printf("wallclock time ............. : %08lx %08lx\n", CounterValue[1], CounterValue[0]);
*CounterSelect = 0x81;
printf("wallclock time, split ...... : %08lx %08lx\n", CounterValue[1], CounterValue[0]);
printf("\n");
}
int main(void)
{
print_current_counters();
print_current_counters();
return 0;
}
</verb></tscreen>
<sect>Copyright<p>
sim65 (and all cc65 binutils) are (C) Copyright 1998-2000 Ullrich von