M30622MA-XXXFP RENESAS [Renesas Technology Corp], M30622MA-XXXFP Datasheet - Page 337

• Manufacturer Part Number: M30622MA-XXXFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY
• Manufacturer: RENESAS [Renesas Technology Corp]

Timer B
322
Operation
Note
Figure 2.3.10. Operation timing of pulse width measurement mode
2.3.5 Operation of Timer B (pulse width measurement mode)
In pulse period/pulse width measurement mode, choose functions from those listed in Table 2.3.4. Op-
erations of the circled items are described below. Figure 2.3.10 shows the operation timing, and Figure
2.3.11 shows the set-up procedure.
Count source
Measurement pulse
Reload register
transfer timing
Timing at which counter
reaches “0000
Count start flag
Timer Bi overflow flag
Timer Bi interrupt request bit
Table 2.3.4. Choosed functions
(1) Setting the count start flag to “1” causes the counter to start counting the count source.
(2) If an effective edge of a pulse to be measured is input, the value of the counter goes to
(3) If an effective edge of a pulse to be measured is input again, the value of the counter is
• The timer Bi interrupt request bit goes to “1” when an effective edge of a pulse to be measured
• The value of the counter at the beginning of a count is indeterminate. Thus there can be in-
• The timer Bi overflow flag goes to “0” if timer Bi mode register is written to when the count start
Count source
Measurement
mode
is input or timer Bi is overflows. The factor of interrupt request can be determined by use of the
timer Bi overflow flag within the interrupt routine.
stances in which the timer Bi overflow flag goes to “1” immediately after a count is performed.
flag is “1”. This flag cannot be set to “1” by software.
16”
“0000
to the reload register. The timer Bi interrupt request does not generate.
transferred to the reload register, and the timer Bi interrupt request bit goes to “1”. Then the
value of the counter becomes “0000
Item
counter
16
”, and measurement is started. In this instance, an indeterminate value is transferred
O
O
“H”
“1”
“0”
“1”
“0”
“1”
“0”
“L”
Internal count source (f
Pulse period measurement (interval between measurement pulse falling edge to falling edge)
Pulse period measurement (interval between measurement pulse rising edge to rising edge)
Pulse width measurement (interval between measurement pulse falling edge to rising edge,
Transfer
(indeterminate
value)
(1) Start count
Note 1: Counter is initialized at completion of measurement.
Note 2: Timer has overflowed.
Cleared to “0” when interrupt request is accepted, or cleared by software
(2) Start measurement
1
(Note 1)
/ f
8
and between rising edge to falling edge)
/ f
16
32
(3) Start measurement again
”, and measurement is started again.
/ fc
Transfer(measured value)
32
(Note 1)
)
Set-up
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(Note 1)
(Note 1)
Mitsubishi microcomputers
M16C / 62 Group
(Note 2)