Lattice LC4064C-5TN100C: A Comprehensive Technical Overview of the CPLD

The Lattice LC4064C-5TN100C represents a classic and enduring architecture within the category of Complex Programmable Logic Devices (CPLDs). Designed for high-performance, low-power control and glue logic applications, this device from Lattice Semiconductor's ispMACH 4000 family continues to be a reliable workhorse in modern electronic designs.

Architectural Foundation: The CPLD Core

At the heart of the LC4064C lies a traditional CPLD structure built upon a sea of Programmable Logic Blocks (PLBs). Each PLB contains macrocells that implement combinatorial and sequential logic functions. The key to a CPLD's deterministic timing is its global, centralized interconnect matrix. Unlike the distributed routing of FPGAs, this matrix ensures that signal delays are highly predictable and consistent across the device, which is critical for state machine and control path applications where timing must be exact.

Key Technical Specifications

The part number itself decodes its core features:

LC4064C: Denotes the family (ispMACH 4000) and the logic density, with "64" indicating 64 macrocells.

-5: Signifies the performance grade, with this device offering a pin-to-pin delay as low as 5 ns, enabling high-speed operation.

TN100C: Indicates the package (Thin Quad Flat Pack, TQFP) and the number of pins (100). The "C" denotes the commercial temperature range (0°C to +70°C).

The device features 64 macrocells, which can be organized into 4 PLBs. It offers up to 69 user I/O pins on the 100-pin package, providing ample connectivity for interfacing with other components like memories, microcontrollers, and ASICs. These I/Os are compliant with various standards, including LVTTL and LVCMOS. A significant advantage of this CPLD family is its low power consumption, operating on a single 3.3V power supply, making it suitable for power-sensitive applications.

In-System Programmability (ISP)

A defining feature of the ispMACH 4000 family is its robust In-System Programmability (ISP). Using a standard 4-wire JTAG (IEEE 1149.1) interface, designers can reprogram the CPLD after it has been soldered onto a printed circuit board (PCB). This capability drastically simplifies the design cycle, facilitates field upgrades, and allows for rapid prototyping and debugging, reducing time-to-market.

Design and Development Ecosystem

Development for the LC4064C is supported by Lattice's ispLEVER Classic design software. This environment provides a complete suite of tools, including design entry (schematic or HDL), synthesis, functional simulation, and fitter (place-and-route) software. The toolchain generates a JEDEC file which is used to program the device via the JTAG port.

Target Applications

The deterministic timing and instant-on capability of the LC4064C make it ideal for numerous applications, including:

Address decoding and bus interfacing in microprocessor systems.

System control logic and power management state machines.

Data routing and signal gating between different subsystems.

Protocol bridging and interface translation (e.g., between SPI and I2C).

Function integration to consolidate multiple simple PALs or GALs into a single, reprogrammable device.

Conclusion

ICGOOODFIND: The Lattice LC4064C-5TN100C stands as a testament to the enduring value of the CPLD architecture. Its combination of predictable timing performance, low power consumption, high integration of glue logic, and reprogrammability secures its place as a fundamental component for control-oriented logic tasks in a vast array of electronic systems, from consumer electronics to industrial controls.

Keywords:

1. CPLD (Complex Programmable Logic Device)

2. Deterministic Timing

3. In-System Programmability (ISP)

4. 64 Macrocells

5. Glue Logic