Lattice ISP1016E-80LT44: A Comprehensive Technical Overview of the In-System Programmable Logic Device

The Lattice ISP1016E-80LT44 represents a significant milestone in the evolution of In-System Programmable (ISP) logic devices. As a high-density programmable logic device (PLD) fabricated with advanced E²CMOS technology, it offers designers a powerful and flexible solution for integrating complex logic functions while dramatically reducing board space and component count.

Architecturally, the ISP1016E is built around a versatile logic cell structure that combines programmable logic arrays with a centralized global routing pool. This specific variant, denoted by the -80LT44 suffix, indicates a commercial temperature grade (0°C to +70°C), a maximum pin-to-pin delay of 80ns, and a 44-pin PLCC (Plastic Leaded Chip Carrier) package. The core consists of 16 generic logic blocks, each containing 18 cells, culminating in a total of 288 programmable logic cells. This provides a equivalent gate count in the range of 2,000 to 4,000, making it suitable for a wide array of applications from state machine control to bus interfacing and address decoding.

The defining feature of this device is its ISP capability, enabled by an on-chip programming state machine. This allows the device to be reconfiguremed after being soldered onto a printed circuit board (PCB). This eliminates the need for physical handling and socketing traditionally associated with programmable devices, streamlining the manufacturing process, facilitating field upgrades, and significantly reducing system downtime for design iterations. Programming is achieved through a standard 4-wire JTAG (IEEE 1149.1) interface, which also supports robust boundary-scan testing for enhanced system-level testability and fault diagnosis.

The device's 44-pin package offers a balanced number of I/O pins, each of which is configurable for various logic standards and features programmable slew rate control to manage switching noise. Internally, it boasts a deterministic, predictable timing model, which simplifies the design process by ensuring that critical path delays are consistent and manageable. Its non-volatile E²CMOS technology ensures that the programmed logic pattern is retained without the need for an external configuration PROM, enhancing system reliability and security.

In application, the ISP1016E-80LT44 was a workhorse for implementing glue logic, combining multiple standard logic ICs into a single, compact package. It found extensive use in telecommunications equipment, computer peripherals, industrial control systems, and networking hardware. Its ability to be updated in-circuit made it particularly valuable for prototyping and for products requiring future feature enhancements or bug fixes.

ICGOODFIND: The Lattice ISP1016E-80LT44 stands as a classic example of early high-density ISP technology. Its integration of a substantial amount of programmable logic with the revolutionary convenience of in-system programmability provided a critical bridge between simpler PLDs and more complex FPGAs, empowering a generation of designers to create more compact, reliable, and field-upgradable electronic systems.

Keywords:

In-System Programmable (ISP)

Programmable Logic Device (PLD)

JTAG Interface

E²CMOS Technology

Logic Cell Architecture