109
108
1
2
3
4
5
6
7
8
NC
NC
V
PE4/AS
PE6/SIZ0
PE7/SIZ1
R/W
PF0/MODCLK
PF1/IRQ1
PF2/IRQ2
PF3/IRQ3
PF4/IRQ4
PF5/IRQ5
PF6/IRQ6
PF7/IRQ7
BERR
V
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
SS
SS
FC0/CS3
FC1/CS4
FC2/CS5
ADDR19/CS6
ADDR20/CS7
ADDR21/CS8
ADDR22/CS9
ADDR23/CS10
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
V
V
DD
SS
PCLK
PWMB
PWMA
NC
HALT
RESET
NC
NC
V
SS
MC68331
V
V
NC
PAI
CLKOUT
DD
V
NC
DD
SS
3
XFC
V
GP7/IC4/OC5/OC1
PGP6/OC4
DD
EXTAL
V
V
V
DD
DD
XTAL
SS
V
SS
NC
PGP5/OC3/OC1
PGP4/OC2/OC1
PGP3/OC1
PGP2/IC3
FREEZE/QUOT
TSC
BKPT/DSCLK
IFETCH/DSI
IPIPE/DSO
RXD
PGP1/IC2
PGP0/IC1
NC
PQS7/TXD
V
NC
V
NC
SS
SS
331 144-PIN QFP
Figure 3-3 Pin Assignments for 144-Pin Package
3.3 Pin Descriptions
The following tables are a summary of the functional characteristics of MCU pins. Ta-
ble 3-1 shows types of output drivers. Table 3-2 shows all inputs and outputs. Digital
inputs and outputs use CMOS logic levels. An entry in the Discrete I/O column indi-
cates that a pin can also be used for general-purpose input, output, or both. The I/O
port designation is given when it applies. Table 3-3 shows characteristics of power
pins. Refer to Figure 3-1 for port organization.
MC68331
OVERVIEW
MOTOROLA
3-5
USER’S MANUAL