178
CHAPTER 8 PULSE WIDTH COUNT TIMER (PWC)
MB89620 series
8.
10
Program Example for Pulse Width Measurement Function
of Pulse Width Count Timer
This section gives a program example for the pulse width measurement function of the
pulse width count timer.
n
Program Example for Pulse Width Measurement Function
l
Processing description
•
Measures the “H” width of a pulse input to the PWC pin (pulse width measurement function).
•
Generates an interrupt when pulse width measurement completes and continues
measurement.
•
The following shows the relationship between the RLBR register value and the measured
pulse width when the source oscillation is 10 MHz and the 4 t
inst
(t
inst
: divide-by-four source
oscillation) count clock is selected.
Pulse width = (256 – RLBR register value)
×
4
×
4/10 MHz (measurement range: 1.6
µ
s to 409.6
µ
s)
l
Coding example
DDR3
EQU
000DH
PCR1
EQU
0014H
; Address of the PWC pulse width control register 1
PCR2
EQU
0015H
; Address of the PWC pulse width control register 2
RLBR
EQU
0016H
; Address of the PWC reload buffer register
EN
EQU
PCR1:7
; Define the counter operation enable bit.
IE
EQU
PCR1:5
; Define the interrupt request enable bit.
IR
EQU
PCR1:1
; Measurement completion interrupt request flag bit
BF
EQU
PCR1:0
; Buffer full flag bit
ILR2
EQU
007DH
; Address of the interrupt level setting register 2
INT_V
DSEG
ABS
; [DATA SEGMENT]
ORG
0FFF0H
IRQ5
DW
WARI
; Set interrupt vector.
INT_V
ENDS
;-----Main program---------------------------------------------------------------------------------------------------------------------------------------------------------------
CSEG
; [CODE SEGMENT]
; Stack pointer (SP) etc. are already initialized.
:
MOV
DDR3,#00000000B
; Set P35/PWC pin as an input.
CLRI
; Disable interrupts.
CLRB
EN
; Stop counter operation.
CLRB
IE
; Disable interrupt request output.
MOV
A,RLBR
; Clear buffer full flag (PCR1: BF).
MOV
ILR2,#11110111B
; Set interrupt level (level 1).
MOV
RLBR,#0E9H
; Counter reload value (interval time)
MOV
PCR2,#10000100B
; Select the pulse width measurement function, 4 t
inst
, and “H” pulse,
MOV
PCR1,#10100000B
; Enable counter operation, disable WTO pin output, enable interrupt
request output, clear underflow (01
H
→
00
H
) interrupt request flag (bit 2),
clear measurement completion interrupt request flag (IR).
SETI
; Enable interrupts.
;-----Interrupt processing routine---------------------------------------------------------------------------------------------------------------------------------------------
WARI
CLRB
IR
; Clear interrupt request flag.
PUSHW
A
XCHW
A,T
PUSHW
A
MOV
A,RLBR
; Read pulse width measurement value and clear BF flag.
:
User processing
:
POPW
A
XCHW
A,T
POPW
A
RETI
ENDS
;--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
END
Summary of Contents for F2MC-8L MB89620 Series
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Page 10: ...MB89620 series ...
Page 11: ...vi MB89620 series ...
Page 17: ...xii MB89620 series ...
Page 18: ...xvi MB89620 series ...
Page 30: ...MB89620 series CHAPTER 1 OVERVIEW 9 Memo ...
Page 34: ...MB89620 series CHAPTER 1 OVERVIEW 13 Memo ...
Page 42: ...MB89620 series CHAPTER 1 OVERVIEW 21 Memo ...
Page 49: ...28 CHAPTER 1 OVERVIEW MB89620 series ...
Page 62: ...MB89620 series CHAPTER 3 CPU 41 Memo ...
Page 78: ...MB89620 series CHAPTER 3 CPU 57 Memo ...
Page 82: ...MB89620 series CHAPTER 3 CPU 61 Memo ...
Page 86: ...MB89620 series CHAPTER 3 CPU 65 Memo ...
Page 90: ...MB89620 series CHAPTER 3 CPU 69 Memo ...
Page 96: ...MB89620 series CHAPTER 3 CPU 75 Memo ...
Page 122: ...MB89620 series CHAPTER 4 I O PORTS 101 Memo ...
Page 144: ...MB89620 series CHAPTER 5 TIMEBASE TIMER 123 Memo ...
Page 149: ...128 CHAPTER 5 TIMEBASE TIMER MB89620 series ...
Page 157: ...136 CHAPTER 6 WATCHDOG TIMER MB89620 series ...
Page 174: ...MB89620 series CHAPTER 7 8 BIT PWM TIMER 153 Memo ...
Page 177: ...156 CHAPTER 7 8 BIT PWM TIMER MB89620 series ...
Page 202: ...MB89620 series CHAPTER 9 16 BIT TIMER COUNTER 181 Memo ...
Page 217: ...196 CHAPTER 9 16 BIT TIMER COUNTER MB89620 series ...
Page 220: ...MB89620 series CHAPTER 10 8 BIT SERIAL I O SERIAL I O 1 AND SERIAL I O 2 199 Memo ...
Page 228: ...MB89620 series CHAPTER 10 8 BIT SERIAL I O SERIAL I O 1 AND SERIAL I O 2 207 Memo ...
Page 245: ...224 CHAPTER 10 8 BIT SERIAL I O SERIAL I O 1 AND SERIAL I O 2 MB89620 series ...
Page 266: ...MB89620 series CHAPTER 13 A D CONVERTER 245 13 Memo ...
Page 283: ...262 CHAPTER 13 A D CONVERTER MB89620 series ...
Page 289: ...268 CHAPTER 14 CLOCK MONITOR FUNCTION MB89620 series ...
Page 306: ...MB89620 series APPENDIX 285 APPEND Memo ...
Page 319: ...298 APPENDIX MB89620 series Memo ...
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