MC146823

® MOTOROLA MC146823 Advance Information CMOS PARALLEL INTERFACE CMOS IHIGH-DENSITY HIGH-PERFORMANCE SILICON-GATE) PARALLEL INTERFACE The MC146823 CMOS parallel interface (CPI) provides a universal means of interfacing external signals with the MC146805E2 CMOS microprocessor and other multiplexed bus microprocessors. The unique MOTEL circuit on-chip allows direct interfacing to most industry CMOS microprocessors, as well as many NMOS MPUs. I The MC146823 CPI includes three bidirectional 8-bit ports or 241/0 pins. Each 1/0 line may be separately established as an input or an output under program control via data direction registers associated with each port. Using the bit change and test instructions of the MC146805E2, each individual 1/0 pin can be separately accessed. All port registers are readlwrite bytes to accommodate read-modify-write instructions. Features include: 24 Individually Programmed 1/0 Pins MOTEL Circuit for Bus Compatibility with Many Microprocessors Multiplexed Bus Compatibility with: MC146805E2, MC6801, MC6803, and Competitive Microprocessors Data Direction Registers for Ports A, B, and C Four Port CliO Pins May Be Used as Control Lines for: Four Interrupt Inputs Input Byte Latch Output Pulse Handshake Activity 15 Registers Addressed as Memory Locations Handshake Control Logic for Input and Output Peripheral Operation Interrupt Output Pin Reset Input to Clear Interrupts and Initialize Internal Registers 3.0 Volt to 5.5 Volt Operatin...