231
8.10.3
Pin Functions
Port 9 pins also function as external interrupt input pins (
,54 to ,54), the A/D converter
trigger input pin (
$'75*), HIF input pins ((&6, &6, ,2:, ,25), the IIC0 I/O pin (SDA0),
the subclock input pin (EXCL), bus control signal I/O pins (
$6/,26, 5', :5, :$,7), and the
system clock () output pin. The pin functions differ between the mode 1, 2, and 3 (EXPE = 1)
expanded modes and the mode 2 and 3 (EXPE = 0) single-chip modes. The port 9 pin functions
are shown in table 8.20.
Table 8.20 Port 9 Pin Functions
Pin
Selection Method and Pin Functions
P97/
:$,7/SDA0
The pin function is switched as shown below according to the combination of operating
mode, bit WMS1 in WSCR, bit ICE in ICCR of IIC0, and bit P97DDR.
Operating
mode
Modes 1, 2, 3 (EXPE = 1)
Modes 2, 3 (EXPE = 0)
WMS1
0
1
—
ICE
0
1
—
0
1
P97DDR
0
1
—
0
1
—
Pin function
P97 input
pin
P97
output pin
SDA0 I/O
pin
:$,7
input
pin
P97 input
pin
P97
output pin
SDA0 I/O
pin
In the H8S/2138 Series, when this pin is set as the P97 output pin, it is an NMOS push-pull
output. SDA0 is an NMOS open-drain output, and has direct bus drive capability.
P96//EXCL
The pin function is switched as shown below according to the combination of bit EXCLE in
LPWRCR and bit P96DDR.
P96DDR
0
1
EXCLE
0
1
0
Pin function
P96 input pin
EXCL input pin
output pin
When this pin is used as the EXCL input pin, P96DDR should be cleared to 0.
P95/
$6/,26/&6
The pin function is switched as shown below according to the combination of operating
mode, bit IOSE in SYSCR, bit HI12E in SYSCR2, and bit P95DDR.
Operating
mode
Modes 1, 2, 3
(EXPE = 1)
Modes 2, 3 (EXPE = 0)
HI12E
—
0
1
P95DDR
—
0
1
—
IOSE
0
1
—
Pin function
$6
output pin
,26
output pin
P95
input pin
P95
output pin
&6
input pin