Lattice Semiconductor ISPLSI1016-60LJ: A Comprehensive Technical Overview of the High-Density Programmable Logic Device

The Lattice Semiconductor ISPLSI1016-60LJ stands as a quintessential representation of high-density in-system programmable logic from a pivotal era in digital design. As a member of the high-performance pLSI/ispLSI 1000E family, this device successfully balanced logic capacity, speed, and power efficiency, making it a popular choice for a wide array of applications, from telecommunications and industrial control to sophisticated test equipment.

Architectural Foundation: The Generic Logic Block (GLB)

At the core of the ISPLSI1016-60LJ lies its innovative architectural unit: the Generic Logic Block (GLB). Labeled as A0 through A7, the device contains a total of 16 GLBs. Each GLB is a versatile structure comprising 18 inputs, a programmable AND/OR/Exclusive OR array, and four output cells that can be configured as registered or combinatorial. This granular structure allows designers to implement complex logic functions efficiently. The interconnection between these GLBs is managed by a Global Routing Pool (GRP), a central switch matrix that ensures efficient and predictable signal routing across the entire device, maximizing performance and minimizing routing delays.

Key Specifications and Performance

The "1016" in its name denotes a generic logic capacity of approximately 2,000 PLD gates, while the "-60" suffix indicates a pin-to-pin delay of 7.5 ns maximum, enabling high-speed operation for its time. The device operates on a standard 5V power supply and is offered in a 44-pin PLCC (Plastic Leaded Chip Carrier) package, denoted by the "LJ" suffix. A critical feature of this family is its in-system programmability (ISP) via the IEEE 1149.1 (JTAG) interface. This allows the device to be reprogrammed while soldered onto the final printed circuit board, drastically simplifying the prototyping, testing, and field-update processes.

Design Security and I/O Flexibility

To protect intellectual property, the ISPLSI1016-60LJ incorporates a robust security bit mechanism. Once programmed, this bit prevents the readback of the configured logic pattern, securing the design from unauthorized copying or reverse engineering. Furthermore, the device features 32 I/O pins, each associated with a dedicated I/O cell. These cells provide flexibility, supporting various input and output configurations, including TTL-compatible inputs and outputs, and programmable bus-hold circuitry.

Application Space

The combination of density, speed, and reprogrammability made the ISPLSI1016-60LJ an ideal solution for integrating glue logic—the miscellaneous discrete logic chips used to interface larger components like CPUs, memory, and peripherals. It was extensively used to implement state machines, address decoders, complex counters, and data path control logic, consolidating what would have been multiple simpler devices into a single, compact, and reliable chip.

ICGOODFIND Summary

The Lattice Semiconductor ISPLSI1016-60LJ is a historically significant high-density CPLD that excelled in integrating complex digital logic. Its architecture, built around Generic Logic Blocks (GLBs) and a Global Routing Pool (GRP), delivered a reliable blend of performance and flexibility. Key strengths included its 7.5ns speed grade, in-system programmability via JTAG, and integrated design security, making it a cornerstone component for 5V system integration and logic consolidation throughout the 1990s and early 2000s.

Keywords:

1. High-Density Programmable Logic

2. In-System Programmability (ISP)

3. Generic Logic Block (GLB)

4. JTAG Interface

5. Glue Logic Integration