m30262f8gp Renesas Electronics Corporation., m30262f8gp Datasheet - Page 98

• Manufacturer Part Number: m30262f8gp
• Description: Renesas 16-bit Cmos Single-chip Microcomputer M16c Family / M16c/20 Series
• Manufacturer: Renesas Electronics Corporation.

Timer B
92
Table 1.13.8. Timer specifications in pulse period/pulse width measurement mode
Figure 1.13.21. Timer Bi mode register in pulse period/pulse width measurement mode
Note 1: An interrupt request is not generated when the first effective edge is input after the timer has started counting.
Note 2: The value read out from the timer Bi register is indeterminate until the second effective edge is
(3) Pulse period/pulse width measurement mode
Count source
Count operation
Count start condition
Count stop condition
Interrupt request generation timing • When measurement pulse's effective edge is input (Note 1)
TBi
Read from timer
Write to timer
In this mode, the timer measures the pulse period or pulse width of an external signal. (See Table 1.13.8.)
Figure 1.13.21 shows the timer Bi mode register in pulse period/pulse width measurement mode. Figure
1.13.22 shows the operation timing when measuring a pulse period. Figure 1.13.23 shows the operation
timing when measuring a pulse width.
IN
pin function
input after the timer has started counting.
Item
Timer Bi mode register
b7
Preliminary Specifications Rev. 0.9
b6
Specifications in this manual are tentative and subject to change.
b5
b4
b3
b2
1
b1
0
b0
Note 1: It is indeterminate when reset. Assume that the count start flag condition is 1 and then the timer Bi
Note 2: Timer B0.
Note 3: Timer B1, timer B2.
Bit symbol
f
• Up count
• Counter value “0000
Count start flag is set (= 1)
Count start flag is reset (= 0)
• When an overflow occurs. (Simultaneously, the timer Bi overflow flag
changes to “1”. Assume that the count start flag condition is “1” and then
the timer Bi overflow flag becomes “1”. If the timer Bi mode register has a
write-access after next count cycle of the timer from the above condition, the
timer Bi overflow flag becomes “0”.)
Measurement pulse input
When timer Bi register is read, it indicates the reload register’s content
(measurement result) (Note 2)
Cannot be written to
TMOD0
TMOD1
1
TCK0
TCK1
MR0
MR1
MR2
MR3
, f
Symbol
TBiMR(i=0 to 2)
overflow flag becomes 1 . If the timer Bi mode register has a write access after next count cycle of
the timer from the above condition, the timer Bi overflow flag becomes 0 . This flag cannot be set to
2
1 by software.
pulse's effective edge and the timer continues counting
, f
8
, f
0 (Must always be 0 in pulse period/pulse width measurement mode; i = 0)
Timer Bi overflow
flag ( Note 1)
Operation mode
select bit
Measurement mode
select bit
Nothing is assigned (i = 1, 2).
In an attempt to write to this bit, write 0 . The value, if read, turns out to be
indeterminate.
Count source
select bit
32
Renesas Technology Corp.
Bit name
, f
039B
C32
Address
16
to 039D
b1 b0
1 0 : Pulse period / pulse width
0 0 : Pulse period measurement (Interval between
0 1 : Pulse period measurement (Interval between
1 0 : Pulse width measurement (Interval between
1 1 : Must not be set.
b7 b6
b3 b2
0 : Timer did not overflow
1 : Timer has overflowed
0 0 : f
0 1 : f
1 0 : f
1 1 : f
16
16
” is transferred to reload register at measurement
measurement pulse's rising edge to rising edge)
measurement mode
measurement pulse's falling edge to falling edge)
measurement pulse's falling edge to rising edge,
and between rising edge to falling edge)
1
8
32
C32
When reset
00XX0000
or f
2
Specification
2
Function
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(Note 2)
(Note 3)
R
W
M16C/26 Group