
iv
Section 7   RAM
...................................................................................................................... 129
7.1 
Overview............................................................................................................................ 129
7.1.1 
Block Diagram...................................................................................................... 129
Section 8   I/O Ports
 ............................................................................................................... 131
8.1 
Overview............................................................................................................................ 131
8.2 
Port 3.................................................................................................................................. 133
8.2.1 
Overview............................................................................................................... 133
8.2.2 
Register Configuration and Description............................................................... 133
8.2.3 
Pin Functions........................................................................................................ 137
8.2.4 
Pin States .............................................................................................................. 138
8.2.5 
MOS Input Pull-Up............................................................................................... 138
8.3 
Port 4.................................................................................................................................. 139
8.3.1 
Overview............................................................................................................... 139
8.3.2 
Register Configuration and Description............................................................... 139
8.3.3 
Pin Functions........................................................................................................ 141
8.3.4 
Pin States .............................................................................................................. 142
8.4 
Port 5.................................................................................................................................. 143
8.4.1 
Overview............................................................................................................... 143
8.4.2 
Register Configuration and Description............................................................... 143
8.4.3 
Pin Functions........................................................................................................ 146
8.4.4 
Pin States .............................................................................................................. 147
8.4.5 
MOS Input Pull-Up............................................................................................... 147
8.5 
Port 6.................................................................................................................................. 148
8.5.1 
Overview............................................................................................................... 148
8.5.2 
Register Configuration and Description............................................................... 148
8.5.3 
Pin Functions........................................................................................................ 150
8.5.4 
Pin States .............................................................................................................. 151
8.5.5 
MOS Input Pull-Up............................................................................................... 151
8.6 
Port 7.................................................................................................................................. 152
8.6.1 
Overview............................................................................................................... 152
8.6.2 
Register Configuration and Description............................................................... 152
8.6.3 
Pin Functions........................................................................................................ 154
8.6.4 
Pin States .............................................................................................................. 154
8.7 
Port 8.................................................................................................................................. 155
8.7.1 
Overview............................................................................................................... 155
8.7.2 
Register Configuration and Description............................................................... 155
8.7.3 
Pin Functions........................................................................................................ 157
8.7.4 
Pin States .............................................................................................................. 157
8.8 
Port 9.................................................................................................................................. 158
8.8.1 
Overview............................................................................................................... 158
8.8.2 
Register Configuration and Description............................................................... 158
8.8.3 
Pin Functions........................................................................................................ 160