interface ti.sysbios.interfaces.ITimer
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Interface for Timer Peripherals Manager

XDCspec summary sourced in ti/sysbios/interfaces/ITimer.xdc
interface ITimer {  ...
// inherits xdc.runtime.IModule
instance:  ...
XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
package ti.sysbios.interfaces;
 
interface ITimer {
module-wide constants & types
    const UInt ANY// Const used to specify any timer = ~0;
 
    enum PeriodType// Timer period units {
        PeriodType_MICROSECS// period in microsecs,
        PeriodType_COUNTS// period in counts
    };
 
    enum RunMode// Timer Run Modes {
        RunMode_CONTINUOUS// periodic and continuous,
        RunMode_ONESHOT// one-shot,
        RunMode_DYNAMIC// dynamically reprogrammed (available on subset of devices)
    };
 
    enum StartMode// Timer Start Modes {
        StartMode_AUTO// timer starts automatically,
        StartMode_USER// timer will be started by user
    };
 
    enum Status// Timer Status {
        Status_INUSE// timer in use,
        Status_FREE// timer is free
    };
 
    typedef Void (*FuncPtr// Timer tick function prototype)(UArg);
module-wide config parameters
    metaonly config Types.Common$ common$// Common module configuration parameters;
module-wide functions
    UInt getNumTimers// Returns number of timer peripherals on the platform();
    ITimer.Status getStatus// Returns timer status (free or in use)(UInt id);
 
 
instance:
per-instance config parameters
    config UArg arg// Argument for tick function = null;
    config Types.FreqHz extFreq// Timer frequency = {
        lo: 0,
        hi: 0
    };
    config UInt32 period// Period of a tick = 0;
    config ITimer.PeriodType periodType// Period type = ITimer.PeriodType_MICROSECS;
    config ITimer.RunMode runMode// Timer run mode = ITimer.RunMode_CONTINUOUS;
    config ITimer.StartMode startMode// Timer start mode = ITimer.StartMode_AUTO;
per-instance creation
    create// Create an instance-object(Int id, ITimer.FuncPtr tickFxn);
per-instance functions
    UInt32 getCount// Read timer counter register();
    Void getFreq// Return timer frequency in Hz(Types.FreqHz *freq);
    ITimer.FuncPtr getFunc// Get Timer function and arg(UArg *arg);
    UInt32 getPeriod// Get timer period in timer counts();
    Void setFunc// Overwrite Timer function and arg(ITimer.FuncPtr fxn, UArg arg);
    Void setPeriod// Set timer period specified in timer counts(UInt32 period);
    Bool setPeriodMicroSecs// Set timer period specified in microseconds(UInt32 microsecs);
    Void start// Reload and start the timer();
    Void stop// Stop the timer();
}
 
const ITimer.ANY
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Const used to specify any timer

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
const UInt ANY = ~0;
 
 
enum ITimer.PeriodType
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Timer period units

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
enum PeriodType {
    PeriodType_MICROSECS,
    // period in microsecs
    PeriodType_COUNTS
    // period in counts
};
 
VALUES
PeriodType_MICROSECS — Period value is in microseconds.
PeriodType_COUNTS — Period value is in counts.
 
enum ITimer.RunMode
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Timer Run Modes

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
enum RunMode {
    RunMode_CONTINUOUS,
    // periodic and continuous
    RunMode_ONESHOT,
    // one-shot
    RunMode_DYNAMIC
    // dynamically reprogrammed (available on subset of devices)
};
 
VALUES
RunMode_CONTINUOUS — Timer is periodic and runs continuously.
RunMode_ONESHOT — Timer runs for a single period value and stops.
RunMode_DYNAMIC — Timer is dynamically reprogrammed for the next required tick.
 
enum ITimer.StartMode
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Timer Start Modes

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
enum StartMode {
    StartMode_AUTO,
    // timer starts automatically
    StartMode_USER
    // timer will be started by user
};
 
VALUES
StartMode_AUTO — Statically created/constructed Timers will be started in BIOS_start(). Dynamically created Timers will start at create() time. This includes timers created before BIOS_start().
StartMode_USER — Timer will be started by the user using start().
 
enum ITimer.Status
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Timer Status

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
enum Status {
    Status_INUSE,
    // timer in use
    Status_FREE
    // timer is free
};
 
VALUES
Status_INUSE — Timer is in use. A timer is marked in use from the time it gets created to the time it gets deleted.
Status_FREE — Timer is free and can be acquired using create.
 
typedef ITimer.FuncPtr
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Timer tick function prototype

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
typedef Void (*FuncPtr)(UArg);
 
 
metaonly config ITimer.common$  // module-wide
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Common module configuration parameters

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
metaonly config Types.Common$ common$;
 
DETAILS
All modules have this configuration parameter. Its name contains the '$' character to ensure it does not conflict with configuration parameters declared by the module. This allows new configuration parameters to be added in the future without any chance of breaking existing modules.
 
ITimer.getNumTimers()  // module-wide
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Returns number of timer peripherals on the platform

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
UInt getNumTimers();
 
RETURNS
Number of timer peripherals.
 
ITimer.getStatus()  // module-wide
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Returns timer status (free or in use)

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
ITimer.Status getStatus(UInt id);
 
RETURNS
timer status
 
config ITimer.arg  // instance
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Argument for tick function

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
config UArg arg = null;
 
DETAILS
Default is null.
 
config ITimer.extFreq  // instance
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Timer frequency

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
config Types.FreqHz extFreq = {
    lo: 0,
    hi: 0
};
 
DETAILS
This parameter is meaningfull only on platforms where the timer's input clock can be changed. If value is left at zero, then input clock to the timer clock is assumed.
This value is used to convert timer ticks to real time units; seconds, milliseconds, etc.
 
config ITimer.period  // instance
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Period of a tick

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
config UInt32 period = 0;
 
DETAILS
The period can be specified in timer counts or microseconds and its default value is 0.
The implementation of ITimer will support a period of UInt32 timer counts and use pre-scalars if necessary.
 
config ITimer.periodType  // instance
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Period type

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
config ITimer.PeriodType periodType = ITimer.PeriodType_MICROSECS;
 
DETAILS
Default is PeriodType_MICROSECS
 
config ITimer.runMode  // instance
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Timer run mode

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
config ITimer.RunMode runMode = ITimer.RunMode_CONTINUOUS;
 
DETAILS
Default is RunMode_CONTINUOUS.
 
config ITimer.startMode  // instance
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Timer start mode

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
config ITimer.StartMode startMode = ITimer.StartMode_AUTO;
 
DETAILS
Default is StartMode_AUTO.
Instance Creation
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XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
create(Int id, ITimer.FuncPtr tickFxn);
// Create an instance-object
ARGUMENTS
id — Timer id ranging from 0 to a platform specific value, or ANY
tickFxn — function that runs upon timer expiry.
DETAILS
Create could fail if timer peripheral is unavailable. To request any available timer use ANY as the id. TimerId's are logical ids. The family-specific implementations map the ids to physical peripherals.
 
ITimer.getCount()  // instance
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Read timer counter register

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
UInt32 getCount();
 
RETURNS
timer counter value
 
ITimer.getFreq()  // instance
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Return timer frequency in Hz

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
Void getFreq(Types.FreqHz *freq);
 
ARGUMENTS
freq — frequency in Hz
DETAILS
This is the effective frequency of the clock incrementing the timer counter register after all scaling factors are taken into account. (including pre-scalars).
 
ITimer.getFunc()  // instance
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Get Timer function and arg

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
ITimer.FuncPtr getFunc(UArg *arg);
 
ARGUMENTS
arg — pointer for returning Timer's function argument
RETURNS
Timer's function
 
ITimer.getPeriod()  // instance
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Get timer period in timer counts

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
UInt32 getPeriod();
 
RETURNS
period in timer counts
 
ITimer.setFunc()  // instance
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Overwrite Timer function and arg

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
Void setFunc(ITimer.FuncPtr fxn, UArg arg);
 
ARGUMENTS
fxn — pointer to function
arg — argument to function
DETAILS
Replaces a Timer object's tickFxn function originally provided in create.
 
ITimer.setPeriod()  // instance
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Set timer period specified in timer counts

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
Void setPeriod(UInt32 period);
 
ARGUMENTS
period — period in timer counts
DETAILS
Timer_setPeriod() invokes Timer_stop() prior to setting the period and leaves the timer in the stopped state.
To dynamically change the period of a timer you must protect against re-entrancy by disabling interrupts. Use the following call sequence to guarantee proper results:
  // disable interrupts if an interrupt could lead to
  // another call to Timer_start().
  key = Hwi_disable();
  Timer_setPeriod(period);
  Timer_start();
  Hwi_restore(key);
ITimer implementation must support UInt32 and use pre-scalars whenever necessary
SIDE EFFECTS
Calls Timer_stop(), and disables the timer's interrupt.
 
ITimer.setPeriodMicroSecs()  // instance
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Set timer period specified in microseconds

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
Bool setPeriodMicroSecs(UInt32 microsecs);
 
ARGUMENTS
period — period in microseconds
DETAILS
A best-effort method will be used to set the period register. There might be a slight rounding error based on resolution of timer period register. If the timer frequency cannot support the requested period, i.e. the timer period register cannot support the requested period, then this function returns false.
Timer_setPeriodMicroSecs() invokes Timer_stop() prior to setting the period and leaves the timer in the stopped state.
To dynamically change the period of a timer you must protect against re-entrancy by disabling interrupts. Use the following call sequence to guarantee proper results:
  // disable interrupts if an interrupt could lead to
  // another call to Timer_start().
  key = Hwi_disable();
  Timer_setPeriodMicroSecs(period);
  Timer_start();
  Hwi_restore(key);
 
ITimer.start()  // instance
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Reload and start the timer

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
Void start();
 
DETAILS
Thread safety must be observed when using the start and stop APIs to avoid possible miss- configuration of the timers and unintended behaviors. To protect against re-entrancy, surround the start/stop invocations with Hwi_disable() and Hwi_restore() calls:
  // disable interrupts if an interrupt could lead to
  // another call to Timer_start().
  key = Hwi_disable();
  Timer_stop();
  ...
  Timer_start();
  Hwi_restore(key);
SIDE EFFECTS
Enables the timer's interrupt.
 
ITimer.stop()  // instance
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Stop the timer

XDCspec declarations sourced in ti/sysbios/interfaces/ITimer.xdc
Void stop();
 
DETAILS
Thread safety must be observed when using the start and stop APIs to avoid possible miss- configuration of the timers and unintended behaviors. To protect against re-entrancy, surround the start/stop invocations with Hwi_disable() and Hwi_restore() calls:
  // disable interrupts if an interrupt could lead to
  // another call to Timer_start().
  key = Hwi_disable();
  Timer_stop();
  ...
  Timer_start();
  Hwi_restore(key);
SIDE EFFECTS
Disables the timer's interrupt.
generated on Thu, 01 Mar 2012 16:58:00 GMT