MC68B21CP-G

I/o Expanders Overview

The MC68B21CP-G is a Peripheral Interface Adapter manufactured by Rochester Electronics, LLC. It is housed in a DIP-40 package and operates with a 5V power supply. The device features an external data bus width of 8 bits and provides 16 I/O lines across two ports. It supports a maximum clock frequency of 2 MHz and functions within a temperature range of -40°C to +85°C.

I/o Expanders Feature Summary

• Provides versatile parallel input/output capabilities through two independent ports
• Supports standard 8-bit microprocessor interfacing via dedicated data bus lines
• Operates reliably at clock speeds up to 2 MHz for synchronous data transfer

I/o Expanders Applications

• Legacy industrial control systems requiring robust peripheral management
• Embedded applications utilizing older Motorola or Freescale processor architectures
• Retrocomputing hardware restoration and maintenance projects

I/o Expanders Procurement Notes

Verify the specific lot marking and manufacturer date code upon receipt, as Rochester Electronics often sources surplus components from various original equipment manufacturers. Confirm that the DIP-40 ceramic package matches the mechanical requirements of the target socket or PCB footprint before integration into production assemblies.

I/o Expanders Selection Notes

Select this component when a legacy PIA interface is required for systems originally designed around the MC6800 or MC6809 families. Ensure the design accommodates the 5V logic levels and the specific timing characteristics defined in the datasheet. Verify that the 2 MHz maximum clock speed meets the system's performance requirements without necessitating faster alternatives.

I/o Expanders Part Context

This part belongs to the MC68B21 family of Peripheral Interface Adapters, widely used in early computing and automation systems. Rochester Electronics continues production of these legacy parts to support long-term maintenance and repair needs where original semiconductor manufacturers have discontinued similar technologies.

I/o Expanders Replacement Considerations

Direct pin-compatible replacements may include the MC68B21P or MC6821 variants, provided voltage and timing specifications align. Cross-reference with other PIA devices only if functional differences in port configuration are acceptable.