202
CHAPTER 8 8/16-BIT CAPTURE TIMER/COUNTER
■
Program Example of Counter Function
●
Processing specifications
•
In the 16-bit mode, timer 0 and timer 1 are used to generate an interrupt whenever the external clock to
be input to the EC pin is counted 5,000 times (1388
H
).
•
The sample program for reading the 16-bit counter value when the counter is in operation is shown
below (READ16).
●
Coding example
DDR3
EQU
000DH
; Address of port 3-direction register
TCCR
EQU
0019H
; Address of capture control register
TCR1
EQU
001AH
; Address of timer 1 control register
TCR0
EQU
001BH
; Address of timer 0 control register
TDR1
EQU
001CH
; Address of timer 1 data register
TDR0
EQU
001DH
; Address of timer 0 data register
TIF0
EQU
TCR0:7
; Defines the timer 0 interrupt request flag bit.
ILR1
EQU
007CH
; Address of interrupt level setting register 2
INT_V
DSEG
ABS
; [DATA SEGMENT]
ORG
0FFF0H
IRQD
DW
WARI
; Sets the interrupt vector.
ENDS
;------------------------Main program---------------------------------------------------------------------------------
CSEG
; [CODE SEGMENT]
; The stack pointer (SP), etc., is already initialized.
:
MOV
DDR3,#00000000B ; Sets the EC pin to input.
CLRI
; Disables the interrupt.
MOV
ILR1,#10111111B
; Sets the interrupt level to 2.
MOV
TDR0,#088H
; Sets the counter value and the lower 8 bits of the
compare value.
MOV
TDR1,#013H
; Sets the counter value and the higher 8 bits of the
compare value.
MOV
TCR1,#00001110B
; Sets timer 1 to 16-bit mode.
MOV
TCR0,#01101111B
; Clears the timer 0 interrupt request flag, allows interrupt
request output, selects an external clock, clears the
counter, starts the operation, and increments the counter
at a rising edge.
SETI
; Enables a CPU interrupt.
;------------------------Data read subroutine-------------------------------------------------------------------------
READ16
MOVW
A,TDR1
; Reads 16 bits from TDR1 and TDR0.
MOVW
A,TDR1
; Reads 16 bits from TDR1 and TDR0 and stores the old
value in the T register.
CMPW
A
; Executes double read check and compares A with T.
BEQ
RET16
; Match and return
Summary of Contents for F2MC-8L F202RA
Page 2: ......
Page 4: ......
Page 32: ...16 CHAPTER 1 OVERVIEW ...
Page 90: ...74 CHAPTER 3 CPU ...
Page 142: ...126 CHAPTER 5 TIME BASE TIMER POPW A RETI ENDS END ...
Page 150: ...134 CHAPTER 6 WATCHDOG TIMER ...
Page 176: ...160 CHAPTER 7 8 BIT PWM TIMER ...
Page 220: ...204 CHAPTER 8 8 16 BIT CAPTURE TIMER COUNTER ...
Page 240: ...224 CHAPTER 9 12 BIT PPG TIMER ...
Page 274: ...258 CHAPTER 11 EXTERNAL INTERRUPT CIRCUIT 2 LEVEL ...
Page 362: ...346 CHAPTER 15 BUZZER OUTPUT ...
Page 390: ...374 CHAPTER 17 FLASH MEMORY ...
Page 419: ...403 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 434: ...418 INDEX ...
Page 436: ......