266
CHAPTER 16 8/16-BIT COMPOSITE TIMER
16.12 Operating Description of PWC Timer Function
This section describes the operations of the PWC timer function for the 8/16-bit
composite timer.
■
Operation of PWC Timer Function
The composite timer requires the settings shown in Figure 16.12-1 to serve as the PWC timer function.
Figure 16.12-1 Settings for PWC Timer Function
When the PWC timer function is selected, the width and cycle of an external input pulse can be measured.
The edges to start and end counting are selected by timer operation mode setting (T00CR0/T01CR0:F3, F2,
F1, F0).
In this operation mode, the counter starts counting from "00
H
" upon detection of the specified count start
edge of an external input signal. Upon detection of the specified count end edge, the count value is
transferred to the 8/16-bit composite timer 00/01 data register (T00DR/T01DR) and the interrupt flag
(T00CR1/T01CR1:IR) and buffer full flag (T00CR1/T01CR1:BF) are set to "1". The buffer full flag is set
to "0" when the 8/16-bit composite timer 00/01 data register (T00DR/T01DR) is read from.
The 8/16-bit composite timer 00/01 data register holds data with the buffer full flag set to "1". Even when
the next edge is detected at this time, the next measurement result is lost as the count value is not
transferred to the 8/16-bit composite timer 00/01 data register.
As the exception, when the H-pulse and cycle measurement (T00CR0/T01CR0:F3, F2, F1, F0 = "1001
B
")
is selected, the H-pulse measurement result is transferred to the 8/16-bit composite timer 00/01 data register
with the BF bit set to "1", but the cycle measurement result is not transferred to the 8/16-bit composite
timer 00/01 data register with the BF bit set to "1". For cycle measurement, therefore, the H-pulse
measurement result must be read before the cycle is completed. Note also that the result of H-pulse
measurement or cycle measurement is lost unless read before the completion of the next H pulse.
To measure the time exceeding the length of the counter, you can use software to count the number of
occurrences of a counter overflow. When the counter causes an overflow, the interrupt flag (T00CR1/
T01CR1:IF) is set to "1". The interrupt service routine can therefore be used to count the number of times
the overflow occurs.
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
T00/01CR0
IFE
C2
C1
C0
F3
F2
F1
F0
❍
❍
❍
❍
❍
❍
❍
❍
T00/01CR1
STA
HO
IE
IR
BF
IF
SO
OE
1
❍
❍
❍
❍
❍
❍
×
TMCR
TO1
TO0
IIS
MOD
FE11
FE10
FE01
FE00
❍
❍
❍
❍
❍
❍
❍
❍
T00/01DR
Holds pulse width measurement value
❍
: Used bit
×: Unused bit
1: Set "1"
0: Set "0"
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......