timer8.asm

此程序是用CYPRESS单片机编写

;
;  ARGUMENTS: fastcall16 BYTE bPeriodValue (passed in A)
;  RETURNS:   Nothing
;  SIDE EFFECTS: 
;    The A and X registers may be modified by this or future implementations
;    of this function.  The same is true for all RAM page pointer registers in
;    the Large Memory Model.  When necessary, it is the calling function's
;    responsibility to perserve their values across calls to fastcall16 
;    functions.
;
 Timer8_WritePeriod:
_Timer8_WritePeriod:
   RAM_PROLOGUE RAM_USE_CLASS_1
   mov   reg[Timer8_PERIOD_REG], A
   RAM_EPILOGUE RAM_USE_CLASS_1
   ret

.ENDSECTION


.SECTION
;-----------------------------------------------------------------------------
;  FUNCTION NAME: Timer8_WriteCompareValue
;
;  DESCRIPTION:
;     Writes compare value into the Compare register (DR2).
;
;     NOTE! The Timer user module must be STOPPED in order to write the
;           Compare register. (Call Timer8_Stop to disable).
;-----------------------------------------------------------------------------
;
;  ARGUMENTS:    fastcall16 BYTE bCompareValue (passed in A)
;  RETURNS:      Nothing
;  SIDE EFFECTS: 
;    The A and X registers may be modified by this or future implementations
;    of this function.  The same is true for all RAM page pointer registers in
;    the Large Memory Model.  When necessary, it is the calling function's
;    responsibility to perserve their values across calls to fastcall16 
;    functions.
;
 Timer8_WriteCompareValue:
_Timer8_WriteCompareValue:
   RAM_PROLOGUE RAM_USE_CLASS_1
   mov   reg[Timer8_COMPARE_REG], A
   RAM_EPILOGUE RAM_USE_CLASS_1
   ret

.ENDSECTION


.SECTION
;-----------------------------------------------------------------------------
;  FUNCTION NAME: Timer8_bReadCompareValue
;
;  DESCRIPTION:
;     Reads the Compare register.
;-----------------------------------------------------------------------------
;
;  ARGUMENTS:    None
;  RETURNS:      fastcall16 BYTE bCompareValue (value of DR2 in the A register)
;  SIDE EFFECTS: 
;    The A and X registers may be modified by this or future implementations
;    of this function.  The same is true for all RAM page pointer registers in
;    the Large Memory Model.  When necessary, it is the calling function's
;    responsibility to perserve their values across calls to fastcall16 
;    functions.
;
 Timer8_bReadCompareValue:
_Timer8_bReadCompareValue:
 bTimer8_ReadCompareValue:                       ; this name deprecated
_bTimer8_ReadCompareValue:                       ; this name deprecated
   RAM_PROLOGUE RAM_USE_CLASS_1
   mov   A, reg[Timer8_COMPARE_REG]
   RAM_EPILOGUE RAM_USE_CLASS_1
   ret

.ENDSECTION


.SECTION
;-----------------------------------------------------------------------------
;  FUNCTION NAME: Timer8_bReadTimerSaveCV
;
;  DESCRIPTION:
;     Returns the value in the Count register (DR0), preserving the
;     value in the compare register (DR2).
;-----------------------------------------------------------------------------
;
;  ARGUMENTS: None
;  RETURNS:   fastcall16 BYTE bCount (value of DR0 in the A register)
;  SIDE EFFECTS:
;     1) May cause an interrupt, if interrupt on Compare is enabled.
;     2) If enabled, Global interrupts are momentarily disabled.
;     3) The user module is stopped momentarily while the compare value is
;        restored.  This may cause the Count register to miss one or more
;        counts depending on the input clock speed.
;     4) The A and X registers may be modified by this or future implementations
;        of this function.  The same is true for all RAM page pointer registers in
;        the Large Memory Model.  When necessary, it is the calling function's
;        responsibility to perserve their values across calls to fastcall16 
;        functions.
;
;  THEORY of OPERATION:
;     1) Read and save the Compare register.
;     2) Read the Count register, causing its data to be latched into
;        the Compare register.
;     3) Read and save the Counter value, now in the Compare register,
;        to the buffer.
;     4) Disable global interrupts
;     5) Halt the timer
;     6) Restore the Compare register values
;     7) Start the Timer again
;     8) Restore global interrupt state
;
 Timer8_bReadTimerSaveCV:
_Timer8_bReadTimerSaveCV:
 bTimer8_ReadTimerSaveCV:                        ; this name deprecated
_bTimer8_ReadTimerSaveCV:                        ; this name deprecated
 bTimer8_ReadCounter:                            ; this name deprecated
_bTimer8_ReadCounter:                            ; this name deprecated

CpuFlags:      equ   0
bCount:        equ   1

   RAM_PROLOGUE RAM_USE_CLASS_2
   mov   X, SP                                   ; X <- stack frame pointer
   add   SP, 2                                   ; Reserve space for flags, count
   mov   A, reg[Timer8_CONTROL_REG]              ; save the Control register
   push  A
   mov   A, reg[Timer8_COMPARE_REG]              ; save the Compare register
   push  A
   mov   A, reg[Timer8_COUNTER_REG]              ; synchronous copy DR2 <- DR0
                                                 ; This may cause an interrupt!
   mov   A, reg[Timer8_COMPARE_REG]              ; Now grab DR2 (DR0) and save
   mov   [X+bCount], A
   mov   A, 0                                    ; Guess the global interrupt state
   tst   reg[CPU_SCR0], CPU_SCR0_GIE_MASK        ; Currently Disabled?
   jz    .SetupStatusFlag                        ;   Yes, guess was correct
   mov   A, FLAG_GLOBAL_IE                       ;    No, modify our guess
.SetupStatusFlag:                                ; and ...
   mov   [X+CpuFlags], A                         ;   StackFrame[0] <- Flag Reg image
   M8C_DisableGInt                               ; Disable interrupts globally
   Timer8_Stop_M                                 ; Stop the timer
   pop   A                                       ; Restore the Compare register
   mov   reg[Timer8_COMPARE_REG], A
   pop   A                                       ; restore start state of the timer
   mov   reg[Timer8_CONTROL_REG], A
   pop   A                                       ; Return result stored in stack frame
   RAM_EPILOGUE RAM_USE_CLASS_2
   reti                                          ; Flag Reg <- StackFrame[0]

.ENDSECTION


.SECTION
;-----------------------------------------------------------------------------
;  FUNCTION NAME: Timer8_bReadTimer
;
;  DESCRIPTION:
;     Performs a software capture of the Count register.  A synchronous
;     read of the Count register is performed.  The timer is NOT stopped.
;
;     WARNING - this will cause loss of data in the Compare register.
;-----------------------------------------------------------------------------
;
;  ARGUMENTS:    None
;  RETURNS:      fastcall16 BYTE bCount, (value of DR0 in the A register)
;  SIDE EFFECTS:
;    May cause an interrupt.
;
;    The A and X registers may be modified by this or future implementations
;    of this function.  The same is true for all RAM page pointer registers in
;    the Large Memory Model.  When necessary, it is the calling function's
;    responsibility to perserve their values across calls to fastcall16 
;    functions.
;
;  THEORY of OPERATION:
;     1) Read the Count register - this causes the count value to be
;        latched into the Compare register.
;     2) Read and return the Count register values from the Compare
;        registers into the return buffer.
;
 Timer8_bReadTimer:
_Timer8_bReadTimer:
 bTimer8_ReadTimer:                              ; this name deprecated
_bTimer8_ReadTimer:                              ; this name deprecated
 bTimer8_CaptureCounter:                         ; this name deprecated
_bTimer8_CaptureCounter:                         ; this name deprecated

   RAM_PROLOGUE RAM_USE_CLASS_1
   mov   A, reg[Timer8_COUNTER_REG]              ; synchronous copy DR2 <- DR0
                                                 ; This may cause an interrupt!
   mov   A, reg[Timer8_COMPARE_REG]              ; Return DR2 (actually DR0)
   RAM_EPILOGUE RAM_USE_CLASS_1
   ret

.ENDSECTION

; End of File Timer8.asm