Section 9 Timers
9.1
Overview
The H8/3887 Series provides six timers: timers A, C, F, G, and a watchdog timer, and an
asynchronous event counter. The functions of these timers are outlined in table 9-1.
Table 9-1 Timer Functions
Event
Waveform
Name
Functions
Internal Clock
ø/8 to ø/8192
(8 choices)
Input Pin Output Pin Remarks
Timer A
• 8-bit interval timer
• Interval function
• Time base
—
—
øW/128 (choice of
4 overflow periods)
• Clock output
ø/4 to ø/32 øW, øW/4 —
to øW/32 (9 choices)
TMOW
—
Timer C
Timer F
• 8-bit timer
ø/4 to ø/8192, øW/4 TMIC
(7 choices)
Up- count/
down-count
controllable by
software or
hardware
• Interval function
• Event counting function
• Up-count/down-count
selectable
• 16-bit timer
ø/4 to ø/32, øW/4
(4 choices)
TMIF
TMOFL
TMOFH
• Event counting function
• Also usable as two
independent 8-bit timers
• Output compare output
function
Timer G
• 8-bit timer
• Input capture function
• Interval function
ø/2 to ø/64, øW/4
(4 choices)
TMIG
—
—
Counter
clearing option
Built-in capture
input signal
noise canceler
Watchdog • Reset signal generated ø/8192
—
timer
when 8-bit counter
overflows
øw/32
179
ETC [ ETC ]
