Lattice LC4032V-75TN48C: A Comprehensive Technical Overview of the CPLD
The Lattice LC4032V-75TN48C represents a classic and enduring architecture within the realm of Complex Programmable Logic Devices (CPLDs). Designed for high-performance, low-power, and cost-sensitive applications, this device continues to be a reliable workhorse for countless design engineers. This overview delves into its core architecture, key specifications, and target applications.
Core Architecture: The Generic Logic Block (GLB)
At the heart of the LC4032V lies Lattice's optimized high-density CPLD architecture. The fundamental building block is the Generic Logic Block (GLB). Each GLB contains 16 macrocells, and the LC4032V contains 2 of these blocks, providing a total of 32 macrocells. This macrocells are interconnected through a global routing pool (GRP), a central switch matrix that ensures efficient and flexible connectivity between all GLBs and input/output pins. This predictable, deterministic interconnect scheme is a hallmark of CPLDs, guaranteeing consistent timing performance regardless of how the design is routed, unlike the more variable routing in FPGAs.
Key Technical Specifications
The part number itself reveals critical information:
LC4032V: Denotes the Lattice CPLD family (4000V) with 32 macrocells.
-75: Indicates a pin-to-pin logic delay of 7.5 ns, enabling high-speed operation for control logic and state machines.
TN48C: Specifies the package (Thin Plastic Quad Flat Pack, 48 pins) and the commercial temperature grade (0°C to +70°C).
The device operates from a 3.3V core voltage with 5V tolerant I/Os, making it ideal for interfacing with both older 5V and newer 3.3V systems. It offers 36 user-I/O pins in the 48-pin package, providing a substantial number of interfaces for its size. The non-volatile, in-system programmable (ISP) technology based on E²CMOS® allows the device to be reconfigured countless times and retains its programming upon power-up without requiring an external boot PROM.
In-System Programmability and Design Support
A significant advantage of the LC4032V is its robust in-system programmability (ISP). Using a standard 4-point JTAG (IEEE 1149.1) interface, designers can program and test the device after it has been soldered onto a printed circuit board (PCB), greatly simplifying the production and debugging process. Lattice provides comprehensive design support through its Lattice Diamond® and ispLEVER® software suites, which offer integrated design entry, synthesis, place-and-route, and verification tools.
Target Applications
The deterministic timing, instant-on capability, and low power consumption of the LC4032V-75TN48C make it perfectly suited for a wide array of applications, including:
Address decoding and bus interfacing in microprocessor systems.
Glue logic integration to consolidate multiple discrete ICs into a single, reprogrammable device.
Power-on reset (POR) and system configuration control.
Data communication and signal bridging between different logic levels.
State machine implementation for simple control sequences.
The Lattice LC4032V-75TN48C remains a highly effective solution for designers needing a small, fast, and reliable programmable logic device. Its strengths lie in its predictable timing model, 5V tolerance, and non-volatile memory, offering a simple and cost-effective alternative to microcontrollers or more complex FPGAs for logic integration and system management tasks.
Keywords:
CPLD, In-System Programmable, Macrocells, Deterministic Timing, Glue Logic
