PAL16R8

The PAL16R8 Family (PAL16L8, PAL16R8, PAL16R6, PAL16R4) includes the PAL16R8-5/4 Series which provides the highest speed in the 20-pin TTL PAL device family, making the series ideal for high-performance applications. The PAL16R8 Family is provided with standard 20-pin DIP and PLCC pinouts and a 28-pin PLCC pinout. The 28-pin PLCC pinout contains seven extra ground pins interleaved between the outputs to reduce noise and increase speed.

The devices provide user-programmable logic for replacing conventional SSI/MSI gates and flip-flops at a reduced chip count.

The family allows the systems engineer to implement the design on-chip, by opening fuse links to configure AND and OR gates within the device, according to the desired logic function. Complex interconnections between gates, which previously required time-consuming layout, are lifted from the PC board and placed on silicon, where they can be easily modified during prototyping or production.

The PAL device implements the familiar Boolean logic transfer function, the sum of products. The PAL device is a programmable AND array driving a fixed OR array.

The AND array is programmed to create custom product terms, while the OR array sums selected terms at the outputs.

In addition, the PAL device provides the following options:
- Variable input/output pin ratio
- Programmable three-state outputs
- Registers with feedback

Product terms with all connections opened assume the logical HIGH state; product terms connected to both true and complement of any single input assume the logical LOW state. Registers consist of D-type flip-flops that are loaded on the LOW-to-HIGH transition of the clock. Unused input pins should be tied to VCC or GND.

The entire PAL device family is supported by the FusionPLD partners. The PAL family is programmed on conventional PAL device programmers with appropriate
personality and socket adapter modules. Once the PAL device is programmed and verified, an additional connection may be opened to prevent pattern readout. This feature secures proprietary circuits.