![](http://datasheet.mmic.net.cn/330000/MB89816A_datasheet_16437152/MB89816A_4.png)
4
MB89810A Series
I
PIN DESCRIPTION
(Continued)
Pin no.
23
24
18
19
21
22
20
Pin name
X0
X1
X0A
X1A
MOD0
MOD1
RST
Circuit type
A
Function
Main clock oscillator pins
I
Subclock crystal oscillator pins
B
Operating mode selection pins
Connect directly these pins directly to V
SS
.
C
Reset I/O pin
This pin is an N-ch open-drain output type with a pull-up resistor
and a hysteresis input type.
“L” is output from this pin by an internal reset source. The internal
circuit is initialized by the input of “L”.
General-purpose I/O ports
A pull-up resistor option is provided.
These ports have the port output inverting function.
General-purpose I/O ports
A pull-up resistor option is provided.
These ports have the port output inverting function.
General-purpose output ports
These ports have the port output inverting function.
General-purpose output ports
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as a pulse width detection enable input (PWE).
PWE input is hysteresis input.
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as the clock I/O for the 8-bit serial I/O (SCK).
SCK input is hysteresis input.
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as the data output for the 8-bit serial I/O (SO).
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as the data input for the 8-bit serial I/O (SI).
SI input is hysteresis input.
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as a pulse width detection output (PWO).
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as a pulse width detection input (PWI).
PWI input is hysteresis input.
General-purpose I/O port
A pull-up resistor option is provided.
Also serves as the toggle output for the 8-bit PWM timer 1 (PTO1).
49 to 42
P00 to P07
D
41 to 34
P10 to P17
D
33 to 30
P20 to P23
F
29 to 26
1
P24 to P27
P30 /PWE
F
E
2
P31/SCK
E
3
P32/SO
D
4
P33/SI
E
5
P34/PWO
D
6
P35/PWI
E
7
P36/PTO1
D