BS2824 Holtek Semiconductor Inc., BS2824 Datasheet - Page 59

• Manufacturer Part Number: BS2824
• Description: Touch Key Mcu
• Manufacturer: Holtek Semiconductor Inc.

Time Base
Rev. 1.00
Timer Program Example
PFD Programming Example
The program shows how the Timer/Event Counter registers are setup along with how the interrupts are
enabled and managed. Note how the Timer/Event Counter is turned on, by setting bit 4 of the Timer
Control Register. The Timer/Event Counter can be turned off in a similar way by clearing the same bit.
This example program sets the Timer/Event Counters to be in the timer mode, which uses the internal
system clock as their clock source.
The device includes a Time Base function which is used to generate a regular time interval signal.
The Time Base time interval magnitude is determined using an internal 13 stage counter sets the
division ratio of the clock source. This division ratio is controlled by both the TBSEL0 and TBSEL1
bits in the CTRL1 register. The clock source is selected using the T0S bit in the TMR0C register.
When the Time Base time out, a Time Base interrupt signal will be generated. It should be noted that
as the Time Base clock source is the same as the Timer/Event Counter clock source, care should be
taken when programming.
org 04h
org 08h
jmp tmr0int
:
org 20h
:
;internal Timer 0 interrupt routine
tmr0int:
:
; Timer 0 main program placed here
:
:
begin:
;setup Timer 0 registers
mov
mov tmr0,a
mov a,081h
mov tmr0c,a
;setup interrupt register
mov a,00dh
mov intc0,a
:
set tmr0c.4
:
a,09bh
:
:
:
:
; external interrupt vector
; Timer Counter 0 interrupt vector
; jump here when Timer 0 overflows
; main program
; setup Timer 0 preload value
; setup Timer 0 control register
; timer mode and prescaler set to /2
; enable master interrupt and both timer interrupts
; start Timer 0
59
BS2824/BS2854/BS2868
Touch Key MCU
January 27, 2010