M37733MHBXXXFP Datasheet, PDF (17/89 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
M37733MHBXXXFP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
TIMER
There are eight 16-bit timers. They are divided by type into timer A(5)
and timer B(3).
The timer I/O pins are also used as I/O pins for ports P5 and P6. To
use these pins as timer input pins, the port direction register bit
corresponding to the pin must be cleared to “0” to specify the input
mode.
TIMER A
Figure 13 shows a block diagram of timer A.
Timer A has four modes; timer mode, event counter mode, one-shot
pulse mode, and pulse width modulation mode. The mode is selected
with bits 0 and 1 of the timer Ai mode register (i = 0 to 4). Each of
these modes is described below.
(1) Timer mode [00]
Figure 14 shows the bit configuration of the timer Ai mode register
during timer mode. Bits 0, 1, and 5 of timer Ai mode register must
always be “0” in the timer mode.
Bit 3 is ignored if bit 4 is “0”.
Bits 6 and 7 are used to select the timer counter source. The counting
of the selected clock starts when the count start flag is “1” and stops
when it is “0”.
Figure 15 shows the bit configuration of the count start flag. The
counter is decremented. An interrupt is caused and the interrupt
request bit of the timer Ai interrupt control register is set when the
contents becomes 000016. At the same time, the contents of the reload
register are transferred to the counter, and count is continued.
Clock source selection
f2
f16
f64
f512
• Timer
• One-shot
• Pulse width modulation
Timer (gate function)
Polarity
TAi IN ^selection
(i = 0 – 4)
Event counter
External trigger
Pulse output
TAi OUT
(i = 0 – 4)
Data bus (odd)
Data bus (even)
(Low-order
8 bits)
(High-order 8 bits)
Reload register(16)
Count start flag
(Address 4016)
Down count
Up-down flag
(Address 4416)
Counter(16)
Up/Down
Always decremented
except in event count mode
Address
Timer A0 4716 4616
Timer A1 4916 4816
Timer A2 4B16 4A16
Timer A3 4D16 4C16
Timer A4 4F16 4E16
Toggle flip-flop
Fig. 13 Block diagram of timer A
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