Lattice LC4128V75TN100-10I: A Comprehensive Technical Overview of the 3V CPLD

In the realm of digital logic design, Complex Programmable Logic Devices (CPLDs) serve as fundamental building blocks for a vast array of applications, from glue logic and bus interfacing to state machine control and power management sequencing. Among these, the Lattice Semiconductor LC4128V75TN100-10I stands out as a robust and highly capable solution, particularly for systems operating at a 3.3V core voltage. This article provides a detailed technical examination of this specific CPLD.

The device's identifier, LC4128V75TN100-10I, concisely encapsulates its key characteristics. The '4128' denotes that it contains 128 macrocells, which are the fundamental logic units within the CPLD. This provides a substantial amount of programmable logic resources for implementing complex combinatorial and sequential logic functions. The 'V' signifies a 3.3V core voltage operation, making it ideal for modern low-power electronic systems. The '75' indicates 75 input/output pins, offering significant connectivity for interfacing with other components like microprocessors, memory, and peripherals. The package is a space-efficient 100-pin Thin Quad Flat Pack (TN100), suitable for dense PCB layouts. Finally, the '-10I' specifies a 10ns maximum pin-to-pin delay, highlighting its high-performance capability with a guaranteed operating frequency of up to 100MHz.

Architecturally, the LC4128V is built around Lattice's proven UltraMOS® technology. Its internal structure is organized into a Programmable Functional Unit (PFU) array. Each PFU contains multiple macrocells, and the interconnect between them is based on a highly deterministic, fast-route Global Routing Pool (GRP). This architecture is a hallmark of CPLDs, offering predictable timing performance crucial for critical control-path applications. Unlike FPGAs, whose routing delays can be less predictable, the CPLD's fixed interconnect ensures that timing models are consistent across designs.

A significant advantage of this family is its in-system programmable (ISP) capability through the IEEE 1149.1 (JTAG) interface. This allows for rapid prototyping and easy field upgrades without removing the chip from the circuit board, drastically reducing development time and cost. Furthermore, the device features 5V tolerant I/O pins, a critical feature for mixed-voltage environments where it must interface with older 5V logic devices without requiring external level shifters.

The combination of low power consumption, high speed, and a large number of I/Os makes the LC4128V75TN100-10I exceptionally versatile. Its primary applications include:

Address Decoding and Bus Interface: Glue logic in microprocessor and microcontroller-based systems.

State Machine Implementation: Designing complex control units with deterministic timing.

Data Routing and Bridging: Protocol bridging and signal gating.

Power-Up Sequencing: Controlling the power-on and power-down sequence of multi-rail systems.

ICGOOODFIND: The Lattice LC4128V75TN100-10I is a high-performance, 3.3V CPLD that offers an optimal blend of density, speed, and I/O capability. Its deterministic architecture, 5V tolerance, and ISP features make it a reliable and efficient choice for a wide range of digital logic tasks in communications, computing, industrial, and consumer applications.

Keywords: CPLD, 3.3V Operation, 128 Macrocells, In-System Programmable (ISP), 5V Tolerant I/O.