MB88311

11111111111111111111111111111111111111111111111111111111111111111 FUJITSU 111111111111111111111111111111111111111111111111 CMOS INPUT/OUTPUT EXPANDER MB 88310 MB 88311 April 1986 Edition 1.0 CMOS INPUT/OUTPUT EXPANDER The Fujitsu MB 88310/MB 88311 are peripheral integrated circuits that can be connected to a 4-bit or 8-bit single·chip microcomputer (MCU) to provide ad· ditional I/O ports. Besides furnishing simple I/O port expansion, the MB 88310 and MB 88311 can AND or OR port data with data from the MCU, on instruc· tion from the MCU. The MB 8831 O/MB 88311 are pseudo·bidirectional ports. They are accessed in 4-bit units, but each individual bit can be used for either input or output, and input and output can be intermixed. The interface to the MCU requires only the connection of a 4-bit interface port and a strobe signal. All output ports of the MB 88310 are open·drain; MB 88311 output ports all have pull·up resistors. The output ports on both chips are reset to the high·i...