The 8255A-5/BQA is a programmable peripheral interface (PPI) chip manufactured by Advanced Micro Devices (AMD). It is a versatile I/O expander that enables a microprocessor to interface with a wide range of peripheral devices. The 8255A-5/BQA provides a flexible means of connecting input/output devices to a microcomputer system.

Applications:

• Interfacing microprocessors with peripherals
• Data acquisition systems
• Industrial control systems
• Keyboard and display interfaces
• General-purpose I/O expansion

Features:

• Three 8-bit I/O ports (Port A, Port B, Port C)
• Programmable operating modes
• Bit set/reset capability on Port C
• TTL compatible inputs and outputs
• Simple interface to microprocessors

Benefits:

• Provides a flexible and cost-effective way to expand I/O capabilities
• Simplifies the interface between a microprocessor and peripherals
• Reduces the need for custom hardware designs
• Offers a variety of operating modes to suit different applications
• Enhances system performance by offloading I/O tasks from the microprocessor

Specifications:

The 8255A-5/BQA operates on a single +5V power supply. It is typically packaged in a 40-pin DIP (Dual In-line Package). The chip features three 8-bit ports: Port A, Port B, and Port C. Port A can be programmed as either an input or output port. Port B can also be configured as an input or output port. Port C can be programmed for bit set/reset capability, allowing individual bits to be set or cleared independently. The operating temperature range is typically 0°C to +70°C.

The programmable modes allow the 8255A-5/BQA to adapt to a variety of applications. Mode 0 is basic I/O, Mode 1 is strobed I/O, and Mode 2 is bidirectional busing. These modes provide the flexibility needed to handle a wide range of peripheral devices. It is an essential component in many legacy embedded systems.