[C5517] Microsecond-resolution real time clock

Hi! Thanks for pointing me to the examples. I changed the examples and came up with the codes below. It is supposed to output a line every second. But it is too fast! The lines are actually 0.7 seconds apart.

Snippet in test.c

Void taskFxn2(Arg value_arg)
{
	LgUns i, j;
	LgUns freq;
    Int value = ArgToInt (value_arg);
    Float onesecond, microSecsPerIntr, hcycles, lcycles, HIntrPerMs, LIntrPerMs;

    /* get frequency of platform */
    freq = GBL_getFrequency();
    printf("GBL Freq: %ld KHz\n", (LgUns)freq);

    lcycles = CLK_cpuCyclesPerLtime();
    printf("Cycles per ltime: %f\n", lcycles);

    LIntrPerMs = (Float)freq/lcycles;
    printf("LIntrPerMs = %lf\n", LIntrPerMs);

    /* compute timeout */
    onesecond = 1000*LIntrPerMs;


    for (i = 0; i < value; i++) {
    	printf("%ld\n", i);
    	TSK_sleep((LgUns)onesecond);
    }
    printf("\n");

    printf("end of task\n");
}

Snippet in test.tcf

bios.CLK.MICROSECONDS = 10; 

var task;
task          = bios.TSK.create("task");
task.priority = 1;
task.fxn      = prog.decl("taskFxn2");
task.arg0     = 12;

Elefant,

How are you measuring the 0.7 secs?
Also, could you please post your full code here? I want to see if I can reproduce your issue.
What version of CCS are you on? the latest is CCS 6.1.2

Lali

Hi.

I measured it with a video camera pointing at the Console tab in CCS.

I am using CCS 6.1.1.00022

clk.c:

#include <std.h>
#include <stdio.h>
#include <log.h>
#include <clk.h>
#include <tsk.h>
#include <gbl.h>
#include "clkcfg.h"

Void taskFxn2(Arg value_arg);

Void main()
{
    printf("Going into function\n");
}

Void taskFxn2(Arg value_arg)
{
	LgUns i;
	LgUns currtime = CLK_gethtime();
	LgUns freq;
	printf("Inside hi-res test function. Current CPU htime = %lu\n", currtime);
    Int value = ArgToInt (value_arg);
    Float onesecond, hcycles, lcycles, HIntrPerMs, LIntrPerMs;

    printf("The task time in task2 is: %d ticks\n", (LgUns)TSK_time());

    /* get frequency of platform */
    freq = GBL_getFrequency();
    printf("GBL Freq: %lu KHz\n", (LgUns)freq);

    /* get cpu cycles per htime and ltime interrupt */
    hcycles = CLK_cpuCyclesPerHtime();
    lcycles = CLK_cpuCyclesPerLtime();
    printf("Cycles per htime: %f\n", hcycles);
    printf("Cycles per ltime: %f\n", lcycles);

    HIntrPerMs = (Float)freq/hcycles;
    LIntrPerMs = (Float)freq/lcycles;

    printf("HIntrPerMs = %lf\n", HIntrPerMs);
    printf("LIntrPerMs = %lf\n", LIntrPerMs);

    /* compute number of interrupts to make 1 second */
    onesecond = 1000*LIntrPerMs;

    printf("task, index, htime, ltime, timeAbs\n");
    for (i = 0; i < value; i++) {
    	printf("2, %lu, %lu, %lu, %lu\n", i, CLK_gethtime(), CLK_getltime(), CLK_gethtime() / CLK_countspms());
    	TSK_sleep((LgUns)onesecond);
    }
    printf("\n");

    printf("end of task2\n");
}

clk.tcf:

utils.loadPlatform("ti.platforms.evm5517");

bios.enableRealTimeAnalysis(prog);
bios.enableMemoryHeaps(prog);
bios.enableRtdx(prog);
bios.enableTskManager(prog);

bios.DARAM.createHeap      = true;
bios.DARAM.enableHeapLabel = true;
bios.DARAM["heapLabel"]    = prog.extern("SEG0");
bios.DARAM.heapSize        = 0x500;
bios.MEM.BIOSOBJSEG = prog.get("DARAM");
bios.MEM.MALLOCSEG = prog.get("DARAM");


bios.GBL.MEMORYMODEL = "LARGE";

bios.CLK.MICROSECONDS = 10; 

var trace;
trace         = bios.LOG.create("trace");
trace.bufLen  = 128;
trace.logType = "circular";

bios.LOG_system.bufLen = 512;

var task;
task          = bios.TSK.create("task");
task.priority = 1;
task.fxn      = prog.decl("taskFxn2");
task.arg0     = 120;

// !GRAPHICAL_CONFIG_TOOL_SCRIPT_INSERT_POINT!

if (config.hasReportedError == false) {
    prog.gen();
}

Console output:

Going into function
Inside hi-res test function. Current CPU htime = 419
The task time in task2 is: 0 ticks
GBL Freq: 200000 KHz
Cycles per htime: 2.000000
Cycles per ltime: 2000.000000
HIntrPerMs = 100000.000000
LIntrPerMs = 100.000000
task, index, htime, ltime, timeAbs
2, 0, 347963, 348, 3
2, 1, 34862636, 34862, 348
2, 2, 69384636, 69384, 693
2, 3, 103907825, 103907, 1039
2, 4, 138433821, 138433, 1384
2, 5, 172961636, 172961, 1729
2, 6, 207485636, 207485, 2074
2, 7, 242010824, 242010, 2420
2, 8, 276537822, 276537, 2765
2, 9, 311065865, 311065, 3110
2, 10, 345594824, 345594, 3455
2, 11, 380122827, 380122, 3801
2, 12, 414650854, 414650, 4146
2, 13, 449178824, 449178, 4491
2, 14, 483706825, 483706, 4837
2, 15, 518234854, 518234, 5182
2, 16, 552764825, 552764, 5527
2, 17, 587293827, 587293, 5872
2, 18, 621822821, 621822, 6218
2, 19, 656352821, 656352, 6563
2, 20, 690883824, 690883, 6908
2, 21, 725412822, 725412, 7254
2, 22, 759943636, 759943, 7599
2, 23, 794469636, 794469, 7944
2, 24, 828995649, 828995, 8289
2, 25, 863524824, 863524, 8635
2, 26, 898054821, 898054, 8980
2, 27, 932585821, 932585, 9325
2, 28, 967115822, 967115, 9671
2, 29, 1001645821, 1001645, 10016
2, 30, 1036178821, 1036178, 10361
2, 31, 1070709854, 1070709, 10707
2, 32, 1105242822, 1105242, 11052
2, 33, 1139773832, 1139773, 11397
2, 34, 1174304649, 1174304, 11743
2, 35, 1208834649, 1208834, 12088
2, 36, 1243365821, 1243365, 12433
2, 37, 1277899822, 1277899, 12778
2, 38, 1312431822, 1312431, 13124
2, 39, 1346965821, 1346965, 13469
2, 40, 1381497822, 1381497, 13814
2, 41, 1416030827, 1416030, 14160
2, 42, 1450563865, 1450563, 14505
2, 43, 1485098649, 1485098, 14850
2, 44, 1519628821, 1519628, 15196
2, 45, 1554162827, 1554162, 15541
2, 46, 1588696865, 1588696, 15886
2, 47, 1623228821, 1623228, 16232
2, 48, 1657759825, 1657759, 16577
2, 49, 1692291865, 1692291, 16922
2, 50, 1726825649, 1726825, 17268
2, 51, 1761356825, 1761356, 17613
2, 52, 1795888825, 1795888, 17958
2, 53, 1830422832, 1830422, 18304
2, 54, 1864955649, 1864955, 18649
2, 55, 1899486649, 1899486, 18994
2, 56, 1934018821, 1934018, 19340
2, 57, 1968550840, 1968550, 19685
2, 58, 2003084636, 2003084, 20030
2, 59, 2037614822, 2037614, 20376
2, 60, 2072148827, 2072148, 20721
2, 61, 2106681636, 2106681, 21066
2, 62, 2141213825, 2141213, 21412
2, 63, 2175746822, 2175746, 21757
2, 64, 2210278865, 2210278, 22102
2, 65, 2244811821, 2244811, 22448
2, 66, 2279343854, 2279343, 22793
2, 67, 2313877824, 2313877, 23138
2, 68, 2348410822, 2348410, 23484
2, 69, 2382942821, 2382942, 23829
2, 70, 2417475840, 2417475, 24174
2, 71, 2452009825, 2452009, 24520
2, 72, 2486540821, 2486540, 24865
2, 73, 2521074854, 2521074, 25210
2, 74, 2555608649, 2555608, 25556
2, 75, 2590140825, 2590140, 25901
2, 76, 2624672822, 2624672, 26246
2, 77, 2659206636, 2659206, 26592
2, 78, 2693738821, 2693738, 26937
2, 79, 2728272854, 2728272, 27282
2, 80, 2762807821, 2762807, 27628
2, 81, 2797342827, 2797342, 27973
2, 82, 2831876825, 2831876, 28318
2, 83, 2866411825, 2866411, 28664
2, 84, 2900946840, 2900946, 29009
2, 85, 2935479649, 2935479, 29354
2, 86, 2970011636, 2970011, 29700
2, 87, 3004541649, 3004541, 30045
2, 88, 3039072821, 3039072, 30390
2, 89, 3073606825, 3073606, 30736
2, 90, 3108141854, 3108141, 31081
2, 91, 3142674824, 3142674, 31426
2, 92, 3177206827, 3177206, 31772
2, 93, 3211740825, 3211740, 32117
2, 94, 3246274821, 3246274, 32462
2, 95, 3280809636, 3280809, 32808
2, 96, 3315341649, 3315341, 33153
2, 97, 3349872821, 3349872, 33498
2, 98, 3384404827, 3384404, 33844
2, 99, 3418938854, 3418938, 34189
2, 100, 3453473865, 3453473, 34534
2, 101, 3488009636, 3488009, 34880
2, 102, 3522541824, 3522541, 35225
2, 103, 3557074821, 3557074, 35570
2, 104, 3591608854, 3591608, 35916
2, 105, 3626143821, 3626143, 36261
2, 106, 3660677822, 3660677, 36606
2, 107, 3695211822, 3695211, 36952
2, 108, 3729745821, 3729745, 37297
2, 109, 3764281821, 3764281, 37642
2, 110, 3798816822, 3798816, 37988
2, 111, 3833351854, 3833351, 38333
2, 112, 3867885824, 3867885, 38678
2, 113, 3902419822, 3902419, 39024
2, 114, 3936954649, 3936954, 39369
2, 115, 3971486821, 3971486, 39714
2, 116, 4006020827, 4006020, 40060
2, 117, 4040554854, 4040554, 40405
2, 118, 4075089825, 4075089, 40750
2, 119, 4109625821, 4109625, 41096

The median time between the iters is 345 ms, but in reality it's more like ~700 ms.

Elefant,

To help debug the timing. Could you please try to integrate the attached project and see if you can post back the timing result? Thanks.

/cfs-file/__key/communityserver-discussions-components-files/791/1817.0675.main.c

/cfs-file/__key/communityserver-discussions-components-files/791/2705.nopRoutine.c

Lali

Hi

overhead of nopRoutine -417
each value run for 120043 cycles

The nopRoutine(15000)  took 19 seconds.

Hi,

I found out one cause of the timing problem. TSK_sleep takes in an unsigned short (max 65535). One second translates to 100000 ticks, so it wrapped around in TSK_sleep. 

The remaining problem is why the timing is doubled in real time: If bios.CLK.MICROSECONDS = 10  (microseconds between interrupts), 50000 ticks should be 0.5 second. But in reality it is 1.0 seconds.

Elefant,

I'm unclear on your question.
Does it have to do with the number of cycles per htime or cycles per ltime? Could you please elaborate.
Regards,

Lali

1. CPU runs at 200 000 kHz

GBL_getFrequency() = 200000   ( units: cycles / milliseconds )

2. I've set bios.CLK.MICROSECONDS = 10 in the tconf so that 10 microseconds should pass between a pair of low-res interrupts (ltime). Thus, 

CLK_cpuCyclesPerLtime() = 2000   ( units: cycles / Lintr )

3. Hence, GBL_getFrequency() / CLK_cpuCyclesPerLtime() = 100    ( units: Lintr / milliseconds )

4. So, if I execute TSK_sleep( 50000 ) in a task, it should sleep for 500 ms.

However, it actually sleeps for 1000 ms. Why?

Perhaps the values reported by GBL_getFrequency(), which is 200000 kHz, is wrong.

Elefant,
I have not taken a look at other possible alternatives, but do you need this function?

Lali