pwm8_1.lis

Application Note Abstract This Application Note introduces a complete and detailed PSoC&reg project

 0012           ;     enable input is asserted high.
 0012           ;
 0012           ;  ARGUMENTS:
 0012           ;     none.
 0012           ;
 0012           ;  RETURNS:
 0012           ;     none.
 0012           ;
 0012           ;  SIDE EFFECTS:
 0012           ;     none.
 0012           ;
 0012           ;  THEORY of OPERATION:  
 0012           ;     Set the start bit in the Control register.
 0012           ;
 0012           ;-----------------------------------------------------------------------------
 0012            PWM8_1_Start:
 0012           _PWM8_1_Start:
 0012 433301       or    REG[PWM8_1_CONTROL_REG], bfCONTROL_REG_START_BIT
 0015 7F           ret  
 0016           
 0016           
 0016           ;-----------------------------------------------------------------------------
 0016           ;  FUNCTION NAME: PWM8_1_Stop
 0016           ;
 0016           ;  DESCRIPTION:
 0016           ;     Disables PWM operation.
 0016           ;
 0016           ;  ARGUMENTS:
 0016           ;     none.
 0016           ;
 0016           ;  RETURNS:
 0016           ;     none.
 0016           ;
 0016           ;  SIDE EFFECTS:
 0016           ;     After this function completes, the Counter register will latch any data
 0016           ;     written to the Period register.  Writing to the Period register is 
 0016           ;     performed using the PWM8_1_WritePeriod function.
 0016           ;
 0016           ;  THEORY of OPERATION:  
 0016           ;     Clear the start bit in the Control register.
 0016           ;
 0016           ;-----------------------------------------------------------------------------
 0016            PWM8_1_Stop:
 0016           _PWM8_1_Stop:
 0016 4133FE       and   REG[PWM8_1_CONTROL_REG], ~bfCONTROL_REG_START_BIT
 0019 7F           ret  
 001A           
 001A           
 001A           ;-----------------------------------------------------------------------------
 001A           ;  FUNCTION NAME: PWM8_1_WritePeriod
 001A           ;
 001A           ;  DESCRIPTION:
 001A           ;     Write the period value into the Period register.
 001A           ;
 001A           ;  ARGUMENTS:
 001A           ;     BYTE  bPeriodValue - period count - passed in the Accumulator.
 001A           ;
 001A           ;  RETURNS:
 001A           ;     none.
 001A           ;
 001A           ;  SIDE EFFECTS:
 001A           ;     If the PWM user module is stopped, then this value will also be
 001A           ;     latched into the Counter register.
 001A           ;
 001A           ;  THEORY of OPERATION:  
 001A           ;     Write data into the Period register.
 001A           ;
 001A           ;-----------------------------------------------------------------------------
 001A            PWM8_1_WritePeriod:
 001A           _PWM8_1_WritePeriod:
 001A 493301       tst   REG[PWM8_1_CONTROL_REG], bfCONTROL_REG_START_BIT
 001D B019         jnz   .CounterRunning
 001F           
 001F           ; Counter is stopped.  Due to chip errata, we have to set the clock low for
 001F           ; the write to the period register to cause the data to be immediately transferred
 001F           ; into the Counter.
 001F           .CounterStopped:
 001F 10           push  X
 0020 5C           mov   X, A                                   ; save the period argument
 0021 7110          or    F, FlagXIOMask
 0023 5D31         mov   A, REG[PWM8_1_INPUT_REG]              ; save the context of the clock - input register
 0025 08           push  A
 0026 4131F0       and   REG[PWM8_1_INPUT_REG], F0h            ; set the clock signal low
 0029 70EF          and   F, ~FlagXIOMask
 002B 5B           mov   A, X                                      
 002C 6031         mov   REG[PWM8_1_PERIOD_REG], A                 ; set the period register with the new period
 002E 18           pop   A
 002F 7110          or    F, FlagXIOMask
 0031 6031         mov   REG[PWM8_1_INPUT_REG], A              ; restore the clock
 0033 70EF          and   F, ~FlagXIOMask
 0035 20           pop   X
 0036 7F           ret
 0037           
 0037           ; Counter is running - write the period into the period register.
 0037           ; Upon Terminal Count this value will get loaded into the counter.
 0037           .CounterRunning:
 0037 6031         mov   REG[PWM8_1_PERIOD_REG], A
 0039 7F           ret
 003A           
 003A           
 003A           ;-----------------------------------------------------------------------------
 003A           ;  FUNCTION NAME: PWM8_1_WritePulseWidth   
 003A           ;
 003A           ;  DESCRIPTION:
 003A           ;     Writes compare value into the PulseWidth register.
 003A           ;
 003A           ;  ARGUMENTS:
 003A           ;     BYTE  bPWidthValue - Pulse Width value count - passed in Accumulator.
 003A           ;
 003A           ;  RETURNS:
 003A           ;     none.
 003A           ;
 003A           ;  SIDE EFFECTS:
 003A           ;     none.
 003A           ;
 003A           ;  THEORY of OPERATION:  
 003A           ;     Write data into the PulseWidth register.
 003A           ;
 003A           ;-----------------------------------------------------------------------------
 003A            PWM8_1_WritePulseWidth:
 003A           _PWM8_1_WritePulseWidth:
 003A 6032         mov   REG[PWM8_1_PWIDTH_REG], A
 003C 7F           ret
 003D           
 003D           
 003D           ;-----------------------------------------------------------------------------
 003D           ;  FUNCTION NAME: bPWM8_1_ReadPulseWidth
 003D           ;
 003D           ;  DESCRIPTION:
 003D           ;     Reads the PulseWidth register.
 003D           ;
 003D           ;  ARGUMENTS:
 003D           ;     none.
 003D           ;
 003D           ;  RETURNS:
 003D           ;     BYTE  bPulseWidth - value read from PulseWidth register - returned
 003D           ;                           in the Accumulator.
 003D           ;
 003D           ;  SIDE EFFECTS:
 003D           ;     none.
 003D           ;
 003D           ;  THEORY of OPERATION:  
 003D           ;     Read the PulseWidth register and return value in A.
 003D           ;
 003D           ;-----------------------------------------------------------------------------
 003D            bPWM8_1_ReadPulseWidth:
 003D           _bPWM8_1_ReadPulseWidth:
 003D 5D32         mov   A, REG[PWM8_1_PWIDTH_REG]
 003F 7F           ret
 0040           
 0040           
 0040           ;-----------------------------------------------------------------------------
 0040           ;  FUNCTION NAME: bPWM8_1_ReadCounter
 0040           ;
 0040           ;  DESCRIPTION:
 0040           ;     Reads the count in the Counter register.
 0040           ;
 0040           ;  ARGUMENTS:
 0040           ;     none.
 0040           ;
 0040           ;  RETURNS:
 0040           ;     BYTE  bCount - current count value in Count register.
 0040           ;
 0040           ;  SIDE EFFECTS:
 0040           ;     Reading the Counter register may cause the Counter register to miss
 0040           ;     one or more counts due to the fact that the clock is stopped while
 0040           ;     the Counter register is read.  The preferred method is to use the 
 0040           ;     interrupt feature to determine when the counter has arrived at a 
 0040           ;     specified value.
 0040           ;
 0040           ;  THEORY of OPERATION:  
 0040           ;     Reading the Counter register causes its value to be latched into the 
 0040           ;     CompareValue register.  Care must be taken to stop the clock and save 
 0040           ;     the CompareValue register's contents before reading the counter.
 0040           
 0040           ;-----------------------------------------------------------------------------
 0040            bPWM8_1_ReadCounter:
 0040           _bPWM8_1_ReadCounter:
 0040           
 0040              ; save the input register clock setting
 0040 7110          or    F, FlagXIOMask
 0042 5D31         mov   A, REG[PWM8_1_INPUT_REG]
 0044 08           push  A
 0045              ; disable the clock
 0045 4131F0       and   REG[PWM8_1_INPUT_REG], ~bfINPUT_REG_CLOCK_MASK
 0048 70EF          and   F, ~FlagXIOMask
 004A           
 004A              ; save the PulseWidth register value
 004A 5D32         mov   A, REG[PWM8_1_PWIDTH_REG]    
 004C 08           push  A
 004D              ; Read the counter. This latches the counter data into
 004D              ; the PulseWidth register.  This may cause an interrupt.
 004D 5D30         mov   A, REG[PWM8_1_COUNTER_REG]    
 004F              ; Read the PulseWidth register, which contains the counter value
 004F 5D32         mov   A, REG[PWM8_1_PWIDTH_REG]    
 0051              ; Save the counter value in X
 0051 5C           mov   X, A
 0052              ; Restore the PulseWidth register
 0052 18           pop   A
 0053 6032         mov   REG[PWM8_1_PWIDTH_REG], A
 0055           
 0055              ; restore the input register clock setting
 0055 7110          or    F, FlagXIOMask
 0057 18           pop   A
 0058 6031         mov   REG[PWM8_1_INPUT_REG], A
 005A 70EF          and   F, ~FlagXIOMask
 005C           
 005C              ; Get the saved read counter value
 005C 5B           mov   A, X
 005D           
 005D 7F           ret
 005E           
 005E           ; end of file