
7542 Group
Rev.3.02 Oct 31, 2006 Page 24 of 134
REJ03B0006-0302
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.
Pin
P0
0
/CAP
0
P0
1
/CMP
0
P0
2
/CMP
1
P0
3
/TX
OUT
P0
4
/RxD
2
P0
5
/TxD
2
P0
6
/S
CLK2
P0
7
/S
RDY2
P1
0
/RxD
1
/CAP
0
P1
1
/TxD
1
P1
2
/S
CLK1
P1
3
/S
RDY1
P1
4
/CNTR
0
P2
0
/AN
0
–P2
7
/AN
7
P3
0
/CAP
1
P3
1
/CMP
2
P3
2
/CMP
3
P3
3
/INT
1
P3
4
P3
5
P3
6
/INT
1
P3
7
/INT
0
V
REF
X
IN
X
OUT
Termination 1
(recommend)
I/O port
Connect to Vss.
When only on-chip
oscillator is used, connect
to V
CC
through a resistor.
When external clock is
input or when on-chip
oscillator is used, open.
Termination 2
When selecting CAP function, per-
form termination of input port.
When selecting CMP
0
function,
perform termination of output port.
When selecting CMP
1
function,
perform termination of output port.
When selecting TX
OUT
function,
perform termination of output port.
When selecting RxD
2
function,
perform termination of input port.
When selecting TxD
2
function,
perform termination of output port.
When selecting external clock input,
perform termination of output port.
When selecting S
RDY2
function,
perform termination of output port.
When selecting RxD
1
function,
perform termination of input port.
When selecting TxD
1
function,
perform termination of output port.
When selecting external clock input,
perform termination of input port.
When selecting S
RDY1
function,
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
2
function,
perform termination of output port.
When selecting CMP
3
function,
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.
-
-
-
Termination 3
-
-
-
-
-
-
When selecting internal clock output,
perform termination of output port.
-
When selecting CAP function, per-
form termination of input port.
-
When selecting internal clock output,
perform termination of output port.
-
When selecting CNTR output function,
perform termination of output port.
-
-
-
-
-
-
-
-
-
-
-
-
Termination 4
When selecting
key-on wakeup
f u n c t i o n , p e r -
form termination
of input port.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Table 7 Termination of unused pins
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
OH(avg)
or I
OL(avg)
.
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.