m37702s1afp Mitsumi Electronics, Corp., m37702s1afp Datasheet - Page 15

• Manufacturer Part Number: m37702s1afp
• Description: Single-chip 16-bit Cmos Microcomputer
• Manufacturer: Mitsumi Electronics, Corp.

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 shared with I/O pins for port P5 and P6. To
use these pins as timer input pins, the data direction register bit
corresponding to the pin must be cleared to “0” to specify input
mode.
TIMER A
Figure 11 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.
Fig. 11 Block diagram of timer A
f
f
f
f
2
16
64
512
f(X
Clock source selection
IN
TAi
)
TAi
(i = 0 – 4)
(i = 0 – 4)
OUT
IN
1/2
Pulse output
selection
Polarity
f
2
1/8
• Timer
• One-shot
• Pulse width modulation
Timer (gate function)
Event counter
External trigger
f
16
1/2
f
M37702M2AXXXFP, M37702M2BXXXFP
32
1/2
Count start flag
Toggle flip-flop
Up-down flag
Down count
(44
(40
f
16
16
(1) Timer mode [00]
Figure 12 shows the bit configuration of the timer Ai mode register
during timer mode. Bits 0, 1, and 5 of the timer Ai mode register
must always be “0” in 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 13 shows the bit configuration of the count start flag. The
counter is decremented, an interrupt is caused and the interrupt
request bit in the timer Ai interrupt control register is set when the
contents becomes 0000
reload register is transferred to the counter and count is contin-
ued.
64
)
)
M37702S1AFP, M37702S1BFP
1/8
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Reload register(16)
Data bus (odd)
Data bus (even)
f
512
Counter(16)
(Lower 8 bits)
Up/Down
MITSUBISHI MICROCOMPUTERS
Always decremented
except in event count mode
16
. At the same time, the contents of the
(Higher 8 bits)
Timer A0 47
Timer A1 49
Timer A2 4B
Timer A3 4D
Timer A4 4F
Addresses
16
16
16
16
16
46
48
4E
4A
4C
16
16
16
16
16
15