IPC@CHIP Documentation - SC12 @CHIP-RTOS V1.10

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TimerProc_Structure
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typedef struct tag_timer_proc
{
unsigned int far *timerID; // pointer to storage the unique timerID
void (far *proc)(); // pointer to the procedure to be executed
void far *dummyptr; // Optional parameter to timer procedure
char name[4]; // -- Field not used -long
interval; // timer execution interval in milliseconds
} TimerProc_Structure;
This structure is defined in the header file rtxapi.h.
Before calling the RTX_INSTALL_TIMER API function the caller must allocate a TimerProc_Structure with the
following members set as specified here:
timerID
Put here a far pointer to a 16 bit location in your program's memory space. The RTX_INSTALL_TIMERAPI
function will output a Timer ID to this referenced location. This Timer ID value is used as handle for this new
timer procedure within the other Timer Procedure API functions.
proc
This is a far vector to your timer procedure. This routine will be called periodically from the kernel. Your timer
procedure should be declared (depending on compiler used) as:
Borland C: void huge MyTimerProc(void)
Microsoft C: void far _saveregs _loadds MyTimerProc(void)
Turbo Pascal:
procedure Timer1_Proc;interrupt;
begin
[... your code ...]
(************************************************)
(* This is needed at the end of the Timer Proc. *)
asm
POP BP
POP ES
POP DS
POP DI
POP SI
POP DX
POP CX
POP BX
POP AX
RETF
end;
(************************************************)
end;
so that the compiler will generate code to set the CPU's DS register, enabling access to your program's data.
Have also a look to some important notesconcerning Timer Procedures.
dummyptr
This four byte value is pushed onto the stack by the system as an input parameter to your timer procedure. You
are free to ignore this parameter as suggested by the above MyTimerProc(void)declarations. Alternatively
you could also use, for example, either of the following timer procedure declarations (Borland):
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