263
CHAPTER 14 16-BIT RELOAD TIMER
14.7 Sample Program of 16-bit Reload Timer
This section gives a program example of the 16-bit reload timer operated in the internal
clock mode and the event count mode:
■Program Example in Internal Clock Mode
●Processing specification
• The 24 ms interval timer interrupt is generated by the 16-bit reload timer 2.
• The repeated interrupts are generated in the reload mode.
• The timer is started using the software trigger instead of the external trigger input.
•EI
2OS is not used.
• The machine clock is 24 MHz; the count clock is 1.33 µs.
●Coding example
ICR04 EQU 0000B4H ;Interrupt control register for 16-bit
;reload timer
TMCSR2 EQU 000064H ;Timer control status register
TMR2 EQU 00794CH ;16-bit timer register
TMRLR2 EQU 00794CH ;16-bit reload register
UF2 EQU TMCSR2:2 ;Interrupt request flag bit
CNTE2 EQU TMCSR2:1 ;Counter operation enable bit
TRG2 EQU TMCSR2:0 ;Software trigger bit
;--------Main program------------------------------------
CODE CSEG
; : ;Stack pointer (SP), already initialized
AND CCR,#0BFH ;Interrupts disabled
MOV I:ICR04,#00H ;Interrupt level 0 (highest)
CLRB I:CNTE2 ;Counter suspended
MOVW I:TMRLR2,#4650H ;Set data for 24 ms timer
MOVW I:TMCSR2,#0000100000011011B
;Operation of interval timer,
clock = 1.33 µs
;External trigger disabled, external
output disabled
;Reload mode selected, interrupt enabled
;Interrupt flag cleared, count started
MOV ILM,#07H ;ILM in PS set to level 7
OR CCR,#40H ;Interrupts enabled
LOOP:
:
Processing by user
: