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Provides the frequency of the IRQ0 high resolution timer (Intel 8254) / Queries the performance timer for its frequency.  
Provides the frequency of the IRQ0 high resolution timer (Intel 8254) / Queries the performance timer for its frequency.


==Syntax==
==Syntax==
  DosTmrQueryFreq (pulTmrFreq)  
  DosTmrQueryFreq (pulTmrFreq)


==Parameters==
==Parameters==
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==Return Code==
==Return Code==
rc (APIRET) - returns
;rc (APIRET) - returns:DosTmrQueryFrequency returns the following values:
 
* 0 NO_ERROR
DosTmrQueryFrequency returns the following values:
* 87 ERROR_INVALID_PARAMETER
* 0         NO_ERROR  
* 535 ERROR_TMR_NO_DEVICE
* 87       ERROR_INVALID_PARAMETER  
* 99 ERROR_DEVICE_IN_USE
* 535       ERROR_TMR_NO_DEVICE  
* 99       ERROR_DEVICE_IN_USE


==Remarks==
==Remarks==
Currently, the timer frequency = 1.19318 Mhz, for a timer resolution of about .838 microseconds. (See also DosTmrQueryTime.)  
Currently, the timer frequency = 1.19318 Mhz, for a timer resolution of about .838 microseconds. (See also [[DosTmrQueryTime]].)


==Example Code==
==Example Code==

Latest revision as of 22:46, 7 January 2024

Provides the frequency of the IRQ0 high resolution timer (Intel 8254) / Queries the performance timer for its frequency.

Syntax

DosTmrQueryFreq (pulTmrFreq)

Parameters

pulTmrFreq (PULONG) - output
Timer Frequency.
Provides the frequency of the IRQ0 high resolution timer in hertz (timer units/sec).

Return Code

rc (APIRET) - returns
DosTmrQueryFrequency returns the following values:
  • 0 NO_ERROR
  • 87 ERROR_INVALID_PARAMETER
  • 535 ERROR_TMR_NO_DEVICE
  • 99 ERROR_DEVICE_IN_USE

Remarks

Currently, the timer frequency = 1.19318 Mhz, for a timer resolution of about .838 microseconds. (See also DosTmrQueryTime.)

Example Code

#define INCL_DOSPROFILE
#include <os2.h>

PULONG    pulTmrFreq;  /*  Timer Frequency. */
APIRET    rc;          /*  Return Code. */

rc = DosTmrQueryFreq(pulTmrFreq);

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