m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 167

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

Fig. 8.4.3 Initial setting example for registers relevant to event counter mode
TIMER B
8.4 Event counter mode
8-16
8.4.2 Setting for event counter mode
Figure 8.4.3 shows an initial setting example for registers relevant to the event counter mode.
Note that when using interrupts, set up to enable the interrupts. For details, refer to section “CHAPTER
6. INTERRUPTS.”
Setting port P5 direction register
b7
(b15)
Setting division ratio
b7
Notes 1: By using bits 0 to 2 of the port P2 pin function control register (address AE
b7
Selecting event counter mode and count polarity
b0
2: When fX
Setting interrupt priority level
Selecting clock source
Pin TB0
Pin TB1
Pin TB2
b7
b7
When a pin is allocated to a port P5 pin (Note 1)
P5 direction register (Address D
IN
IN
IN
Setting count start bit to “1”
b7
32
Clear the corresponding bit to
(Note 2)
is selected as the count source in timer B2 (in other words, when bit 6 at address 63
0
(b8)
b0
0 1
b7
7905 Group User’s Manual Rev.1.0
b0
b3 b2
Selection of event counter mode
Count polarity select bits
0 0 : Count at falling edge of external signal.
0 1 : Count at rising edge of external signal.
1 0 : Count at both of falling and rising edges of external signal.
1 1 : Do not selected.
b0
b0
Timer Bi mode register (i = 0 to 2) (Addresses 5B
Timer B2
Timer B2 clock source select bit
0 : Count an external signal input to the TB2
1 : Count fX
Interrupt priority level select bits
When using interrupts, set these bits to one of levels 1 to 7.
When disabling interrupts, set these bits to level 0.
Particular function select register 1
(Address 63
Can be set to “0000
Timer Bi interrupt control register (i = 0 to 2)
(Addresses 7A
16
b0
)
Timer B2 count start bit
Timer B0 count start bit
Timer B1 count start bit
“
Count start register 0 (Address 40
0.
32
”
16
Timers B0 and B1
)
16
b0
Note: The counter divides the count source by (n + 1).
to 7C
16
Setting port P2 direction register
” to “FFFF
b7
Timer B0 register (Addresses 51
Timer B1 register (Addresses 53
Timer B2 register (Addresses 55
16
)
16
: It may be either “0” or “1.”
” (n).
IN
pin
16
b0
)
16
16
When a pin is allocated to a port P2 pin (Note 1)
Pin TB0
Pin TB1
Pin TB2
), be sure to set the pin allocation. (See Figure 8.2.5.)
to 5D
P2 direction register (Address 8
16
16
16
16
, 50
, 52
, 54
IN
IN
IN
)
16
16
16
Clear the corresponding bit to
)
)
)
(Note 2)
Count starts.
16
= 1), this setting is unnecessary.
16
)
“
0.
”