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7542 Group
Termination of unused pins
• Termination of common pins
I/O ports:
Select an input port or an output port and follow
each processing method.
Output ports: Open.
Input ports: If the input level become unstable, through current
flow to an input circuit, and the power supply current
may increase.
Table 7 Termination of unused pins
Pin
Termination 1
(recommend)
P0
/CAP
I/O port
0
0
P0
/CMP
1
0
P0
/CMP
2
1
P0
/TX
3
OUT
P0
/RxD
4
2
P0
/TxD
5
2
P0
/S
6
CLK2
P0
/S
7
RDY2
P1
/RxD
/CAP
0
1
0
P1
/TxD
1
1
P1
/S
2
CLK1
P1
/S
3
RDY1
P1
/CNTR
4
0
P2
/AN
–P2
/AN
0
0
7
7
P3
/CAP
0
1
P3
/CMP
1
2
P3
/CMP
2
3
P3
/INT
3
1
P3
4
P3
5
P3
/INT
6
1
P3
/INT
7
0
Connect to Vss.
V
REF
X
When only on-chip
IN
oscillator is used, connect
to V
CC
X
When external clock is
OUT
input or when on-chip
oscillator is used, open.
Rev.3.02
Oct 31, 2006
REJ03B0006-0302
When selecting CAP function, per-
form termination of input port.
When selecting CMP
perform termination of output port.
When selecting CMP
perform termination of output port.
When selecting TX
perform termination of output port.
When selecting RxD
perform termination of input port.
When selecting TxD
perform termination of output port.
When selecting external clock input,
perform termination of output port.
When selecting S
perform termination of output port.
When selecting RxD
perform termination of input port.
When selecting TxD
perform termination of output port.
When selecting external clock input,
perform termination of input port.
When selecting S
perform termination of output port.
When selecting CNTR input function,
perform termination of input port.
When selecting AN function, per-
form termination of input port.
When selecting CAP function, per-
form termination of input port.
When selecting CMP
perform termination of output port.
When selecting CMP
perform termination of output port.
When selecting INT function, per-
form termination of input port.
When selecting INT function, per-
form termination of input port.
When selecting INT function, per-
form termination of input port.
through a resistor.
Page 24 of 134
Especially, when expecting low consumption current
(at STP or WIT instruction execution etc.), pull-up or
pull-down input ports to prevent through current
(built-in resistor can be used).
We recommend processing unused pins through a
resistor which can secure I
Because, when an I/O port or a pin which have an
output function is selected as an input port, it may
operate as an output port by incorrect operation etc.
Termination 2
function,
0
function,
1
function,
OUT
function,
2
function,
2
When selecting internal clock output,
perform termination of output port.
function,
RDY2
When selecting CAP function, per-
function,
1
form termination of input port.
function,
1
When selecting internal clock output,
perform termination of output port.
function,
RDY1
When selecting CNTR output function,
perform termination of output port.
function,
2
function,
3
-
-
-
-
-
or I
OH(avg)
Termination 4
Termination 3
When selecting
-
key-on wakeup
f u n c t i o n , p e r -
-
form termination
of input port.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
.
OL(avg)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
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