CP82C55A

Overview

The Renesas CP82C55A is a CMOS Programmable Peripheral Interface (PPI) designed as a high-performance, low-power alternative to the industry-standard NMOS 8255A. It provides 24 programmable I/O pins organized into three 8-bit ports (Port A, Port B, and Port C), which can be configured for various data transfer modes. The device operates with a supply voltage range of 4.5V to 5.5V and supports clock frequencies up to 8MHz without wait states. It features TTL compatibility across its full operating temperature range and includes bus hold circuitry to eliminate the need for external pull-up resistors.

Feature Summary

• Fully pin-compatible with the legacy NMOS 8255A while offering enhanced static CMOS performance and lower power consumption.
• Supports direct bit set/reset capability on Port C, allowing individual control of specific output lines without affecting others.
• Enhanced control word read capability enables the CPU to verify the current configuration state of the peripheral interface.
• Integrated bus hold circuitry maintains stable logic levels on unconnected inputs, removing the requirement for external pull-up components.

Applications

• Interface between 80C86/80C88 microprocessors and peripheral devices requiring parallel I/O expansion.
• Industrial control systems utilizing standard 8-bit microprocessor architectures for sensor and actuator interfacing.
• Legacy system upgrades where NMOS 8255A functionality is required but with improved power efficiency and speed.

Procurement Notes

Verify the specific suffix designation (e.g., -5Z) to confirm the package type, temperature range, and RoHS compliance status, as these attributes vary within the product line. Confirm availability status directly with authorized distributors or the manufacturer, as this component may be subject to discontinuation notices or limited production runs. Ensure that the ordering documentation explicitly references the complete part number to avoid confusion with non-compliant or obsolete variants.

Selection Notes

Select the CP82C55A when a drop-in replacement for the 8255A is needed in designs requiring lower standby power and higher operational speeds. Consider the available package options, such as PDIP or PLCC, based on the board layout constraints and mounting requirements. Verify that the system's voltage levels are compatible with the 4.5V to 5.5V supply range and that the maximum clock frequency meets the timing requirements of the host microprocessor.

Part Context

The CP82C55A belongs to the 82C55 family of programmable peripheral interfaces manufactured by Renesas Electronics (formerly Intersil). This family represents the CMOS evolution of the classic 8255A standard, providing equivalent functionality with modern process technology benefits. It is commonly found in embedded systems, test equipment, and industrial automation controllers that rely on established 8-bit microprocessor ecosystems.

Replacement Considerations

The CP82C55A is functionally equivalent to the Intel 8255A and Harris HA1-8255. For direct replacements, consider the ID82C55A or IP82C55AZ from Renesas/Intersil, ensuring package and temperature grade compatibility. Other CMOS equivalents like the AMD Am7C55 may require verification of pinout and electrical characteristics against the original design specifications.