CHAPTER 9 TIMER/COUNTER FUNCTION
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User’s Manual U15195EJ5V0UD
(5) Timer 3 output control register (TO3C)
TO3C is a register that controls output of the TO3 pin.
This register can be read/written in 8-bit or 1-bit units.
Caution The TO3 output stop status can be canceled by writing 0 to the TO3SP bit of this register.
7
0
TO3C
6
0
5
0
4
0
3
0
2
0
1
0
<0>
TO3SP
Address
FFFFF6A0H
After reset
00H
Bit position
Bit name
Function
0
TO3SP
Validates or invalidates output stop control of the TO3 pin by INTP4 pin input.
0: Invalidates INTP4 pin input
(TO3 output (the output buffer of the TO3 pin is on)).
1: Validates INTP4 pin input
(TO3 output is stopped by the valid edge of the INTP4 pin (the output buffer of
the TO3 pin is off and the TO3 pin goes into a high-impedance state)).
The following table indicates the relationship between the setting of each register and the status of the TO3,
P27, and INTP31 pins.
Table 9-14. Relationship Between Setting of Each Register and Status of TO3, P27, and INTP31 Pins
TO3/P27/INTP31
PMC27
Bit
PFC27
Bit
PM27
Bit
TO3SP
Bit
Operation Mode of Pin
Output Buffer Status
Pin Function
0
×
0
×
Output port mode
On
Output port
0
×
1
×
Input port mode
Off
Input port
1 0
×
×
INTP31 input mode
Off
INTP31
1 1
×
0 On
TO3
1 1
×
1
TO3 output mode
On/off
Note
TO3/Hi-Z
Note
Note
If the TO3SP bit is set to 1 in TO3 output mode (PMC27 bit = 1 and PFC27 bit = 1), the output buffer of the
TO3 pin is turned off and the TO3 pin goes into a high-impedance state if the specified valid interrupt edge
is generated on the INTP4 pin.
To avoid turning off the output drive by valid edge input to the INTP4 pin, be sure to clear the TO3SP bit to
0.
The valid edge of the INTP4 pin is specified by bit 0 (ES40) and bit 1 (ES41) of the INTM2 register.
Specifying the valid edge of the INTP4 pin (changing the ES40 and ES41 bits) is prohibited while timer 3 is
operating.
Remark
×
: Don’t care (does not have to be set)