M37754 Mitsubishi, M37754 Datasheet - Page 33

• Manufacturer Part Number: M37754
• Description: SINGLE-CHIP 16BIT CMOS MICROCOMPUTER
• Manufacturer: Mitsubishi

TIMER B
Figure 35 shows a block diagram of timer B.
Timer B has three modes: timer mode, event counter mode, and
pulse period measurement/pulse width measurement mode. The
mode is selected with bits 0 and 1 of the timer Bi mode register (i=0
to 2). Each of these modes is described below.
(1) Timer mode [00]
Figure 36 shows the bit configuration of the timer Bi mode register
during timer mode. Bits 0 and 1 of the timer Bi mode register must
always be “0” in timer mode.
Bits 6 and 7 are used to select the clock source. The counting of the
selected clock starts when the count start bit is “1” and stops when
“0”.
Fig. 35 Timer B block diagram
(i = 0 – 2)
TBi
Pf
Pf
Pf
Pf
Note: Perform write and read to/from timer Bi register in the condition of 16-bit data length : data length flag (m) =“0”.
2
16
64
512
IN
Clock source selection
Polarity selection
and edge pulse
generator
• Timer
• Pulse period measurement/Pulse
width measurement
Event counter
M37754M8C-XXXGP, M37754M8C-XXXHP
Count start bit
Counter reset
(40
circuit
16
)
As shown in Figure 19, the timer Bi count start bit is at the same ad-
dress as the timer Ai count start bit. The count is decremented, an
interrupt occurs, and the interrupt request bit in the timer Bi interrupt
control register is set when the contents becomes 0000
same time, the contents of the reload register is stored in the counter
and count is continued.
Timer Bi does not have a pulse output function or a gate function like
timer A.
When data is written to timer Bi halted, it is written to the reload reg-
ister and the counter. When data is written to timer Bi which is busy,
the data is written to the reload register, but not to the counter. The
new data is reloaded from the reload register to the counter at the
next reload time and counting continues.
The contents of the counter can be read at any time.
M37754S4CGP, M37754S4CHP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Reload register (16)
Data bus (even)
Data bus (odd)
Counter (16)
(Lower 8 bits)
MITSUBISHI MICROCOMPUTERS
(Higher 8 bits)
Timer B0 51
Timer B1 53
Timer B2 55
Addresses
16
16
16
16
50
52
54
. At the
16
16
16
33