Lattice Semiconductor ISPLSI1032-60LJ: A Comprehensive Technical Overview of the High-Density CPLD
The Lattice Semiconductor ISPLSI 1032-60LJ represents a significant milestone in the evolution of Complex Programmable Logic Devices (CPLDs). As a member of the high-performance ispLSI 1000E family, this device combines high density with in-system programmability (ISP), making it a versatile solution for a wide array of digital logic applications, from telecommunications and networking to industrial control and computing systems.
Architectural Prowess: The Generic Logic Block (GLB) Core
At the heart of the ISPLSI1032-60LJ lies its sophisticated architecture, built around a Global Routing Pool (GRP) that connects multiple Generic Logic Blocks (GLBs). This structure provides a predictable, fast, and flexible interconnect scheme, a hallmark of CPLDs that distinguishes them from FPGAs.
High Logic Density: The "1032" in its name denotes 32 GLBs, each containing 16 macrocells, resulting in a total of 512 logic gates (a generic measure of complexity). This high density allows designers to integrate numerous discrete logic ICs into a single, compact package.
Generic Logic Blocks (GLBs): Each GLB is a self-contained unit with 18 inputs from the GRP, a programmable AND/OR array, and logic分配 registers. This allows for the efficient implementation of complex combinatorial and sequential logic functions.
In-System Programmability (ISP): A defining feature, facilitated by the is p (in-system programmable) prefix, allows the device to be reconfigured soldered directly onto its printed circuit board (PCB). This drastically simplifies prototyping, field upgrades, and design iterations, reducing time-to-market and manufacturing costs.
Performance and Timing Characteristics
The "-60LJ" suffix provides key performance and packaging information. The "-60" indicates a pin-to-pin delay of 7.5 ns maximum, enabling high-speed operation for critical control path applications. The "LJ" denotes a 84-pin PLCC (Plastic Leaded Chip Carrier) package, a common through-hole package offering robust mechanical stability.
The device features a 5.0V core voltage supply, typical for CPLDs of its era, ensuring strong noise immunity and compatibility with contemporary TTL logic levels. Its deterministic timing model, thanks to the fixed interconnect architecture, allows designers to achieve reliable and predictable performance after place-and-route, simplifying the design verification process.
Key Features and System Integration
The ISPLSI1032-60LJ is equipped with features that enhance its system-level integration capabilities:
96 I/O Pins: Offering a high number of user I/Os for interfacing with external components like memories, buses, and other peripherals.
Programmable Macrocell: Each macrocell within a GLB can be individually configured for combinatorial or registered operation, with programmable clocking and reset sources.
Boundary Scan Test (IEEE 1149.1): Integrated support for JTAG boundary scan simplifies board-level testing, allowing for advanced debugging and validation of PCB connections without physical probes.
Application Domains
This CPLD was engineered for applications requiring glue logic integration, state machine control, and high-speed address decoding. Its primary roles included:
Bus Interface and Bridging: Connecting microprocessors to various peripherals with custom timing requirements.
State Machine Implementation: Replacing multiple simpler PLDs to create complex control logic.
Data Path Control: Managing data flow in communication and networking equipment.
The Lattice Semiconductor ISPLSI1032-60LJ stands as a classic example of a high-density, high-performance CPLD from the late 1990s and early 2000s. Its blend of predictable timing, high I/O count, and revolutionary in-system programmability made it a workhorse for digital designers. While newer, lower-power, and higher-density devices have since emerged, the architectural principles it embodied continue to be relevant. It remains a testament to Lattice's innovation in providing flexible logic solutions that effectively bridged the gap between simple PLDs and more complex FPGAs.
Keywords:
1. High-Density CPLD
2. In-System Programmability (ISP)
3. Generic Logic Block (GLB)
4. Deterministic Timing
5. Logic Integration
