8355/8755 Multifunction Device (memory+IO)

• Features
• Block diagram
• Port and DDR addresses

---

Features

• 2kbytes ROM(8355) / EPROM(8755)
• Two bidirectional 8 bit I/O ports
• Each port line individually programmable for I or O
• Internal AD demux using ALE
• Generates ready signal
• Separate control lines for I/O section

---

Block diagram

• Vdd=25V for programming EPROM
• Vcc=5V, Vss=0V

---

Port and DDR addresses

A1	A0	Port/DDR
0	0	Port A
0	1	Port B
1	0	DDR A
1	1	DDR B

DDR=Data Direction Register (1=Output, 0=input)

---