
16
7510 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
Timer Y
Timer Y is a 16-bit timer that can be selected in one of four modes.
Timer mode
The timer counts f(X
IN
)/16 (or f(X
CIN
)/16, if the selected system
clock 
φ
 is f(X
CIN
)/2).
Period measurement mode
CNTR
1
 interrupt request is generated at rising/falling edge of
CNTR
1
 pin input signal. Simultaneously, the value in timer Y latch
is reloaded in timer Y and timer Y continues counting down. Except
for the above-mentioned, the operation in period measurement
mode is the same as in timer mode.
The timer value just before the reloading at rising/falling of CNTR
1
pin input signal is retained until the timer Y is read once after the
reload.
The rising/falling timing of CNTR
1
 pin input signal is found by
CNTR
1
 interrupt.
Event counter mode
The timer counts signals input through the CNTR
1
 pin. Except for
this, the operation in event counter mode is the same as in timer
mode.
Pulse width HL continuously measurement mode
CNTR
1
 interrupt request is generated at both rising and falling
edges of CNTR
1
 pin input signal. Except for this, the operation in
pulse width HL continuously measurement mode is the same as in
period measurement mode.
Note on CNTR
1
 Interrupt Active Edge
Selection
CNTR
1
 interrupt active edge depends on the CNTR
1
 active edge
selection bit. However, in pulse width HL continuously measure-
ment mode, CNTR
1
 interrupt request is generated at both rising
and falling edges of CNTR
1
 pin input signal regardless of the set-
ting of CNTR
1
 active edge selection bit.
Fig. 11  Structure of timer Y mode register
Not used (return “0” when read)
Timer Y operation mode bits
b5 b4
 0   0 : Timer mode
 0   1 : Period measurement mode
 1   0 : Event counter mode
 1   1 : Pulse width HL continuously
           measurement mode
CNTR
1 
active edge selection bit
      0 : Count at rising edge in event counter mode
           Measure the falling edge to falling edge
           period in period measurement mode
           Falling edge active for CNTR
1
 interrupt
      1 : Count at falling edge in event counter mode
           Measure the rising edge to rising edge
           period in period measurement mode
           Rising edge active for CNTR
1
 interrupt
Timer Y stop control bit
 0 : Count start
 1 : Count stop
b7
Timer Y mode register
(TYM : address 0028
16
)
b0