All PALCE20V8 Family Families

Home > Product > Lattice Semiconductor > PALCE20V8 Family

PALCE20V8 Family

An improved PAL device called the PALCE20V8 was created using low-power, high-speed, electrically erasable CMOS technology. It offers a universal device architecture through its macrocells. The PALCE20V8 can immediately replace the majority of 24-pin combinatorial PAL devices as well as PAL20R8 series devices and is completely compatible with the GAL20V8. Device logic is automatically set up in accordance with the design specifications provided by the user. Any of a variety of well-liked design software programs can be used to implement a design, and they all enable the automatic development of a programming file based on Boolean or state equations. Design software can also offer test vectors for the finished gadget and confirms the design. Standard PAL device programmers can be used for programming. The PALCE20V8 employs the well-known sum-of-products (AND/OR) architecture, allowing users to quickly and effectively design complex logic operations. Combinatorial logic at several levels can always be converted to sum-of-products form by making use of the extremely wide input gates included in PAL devices. Through electrically erasable floating-gate cells in the AND logic array, the equations are encoded into the gadget.For logic functions, the fixed OR array permits up to eight data product terms per output. The output macrocell is fed by the aggregate of these products. Each macrocell has a registered or combinatorial active-high or active-low output that can be configured. Four multiplexers are controlled by two global bits and one local bit in each macrocell, which decide the output configuration.

FUNCTIONAL DESCRIPTION

The PALCE20V8 is an all-purpose PAL gadget. Eight independently programmable macrocells (MC0-MC7) make up this device. Each macrocell has three different configuration options: registered output, combinatorial output, combinatorial I/O, and dedicated input. A fixed OR logic array is driven by a programmable AND logic array that is implemented in the programming matrix. In order to enable user-programmable input signal polarity, buffers for device inputs include complimentary outputs. Array inputs or the clock (CLK) and output enable (OE) for every flip-flop are respectively located on pins 1 and 13. Unused input pins ought to be connected directly to GND or VCC. Product terms with both the true and complement of any input signal connected assume a logical LOW state, while product terms with all bits unprogrammed (disconnected) assume the logical HIGH state. The user's design specification, which can be in a variety of forms, is automatically adjusted to the programmable functionalities on the PALCE20V8. Development software processes the design specification to validate the design and generate a programming file. When this file is downloaded to a programmer, the device is configured to perform the user's intended function. The PALCE20V8 offers the customer two design possibilities. It can first be set up as a PAL emulator device. This applies to the majority of 24-pin combinatorial PAL devices and the PAL20R8 series. Device codes for the PALCE20V8's compatible standard PAL architectures will be provided by the manufacturer of the PAL device programmer. The PALCE20V8 will be programmed according to the appropriate PAL device architecture. By doing this, the user can use the JEDEC files for conventional PAL devices without altering them. As an alternative, the device can be directly programmed as a PALCE20V8. The PALCE20V8 device code must be entered in this case. With this choice, the macrocells are fully utilized, enabling the construction of non-standard topologies.

FEATURE

◆ Pin and function compatible with all PAL 20V8 devices

◆ Electrically erasable CMOS technology provides reconfigurable logic and full testability

◆ High-speed CMOS technology

— 5-ns propagation delay for “-5” version

— 7.5-ns propagation delay for “-7” version

◆ Direct plug-in replacement for a wide range of 24-pin PAL devices

◆ Programmable enable/disable control

◆ Outputs individually programmable as registered or combinatorial

◆ Peripheral Component Interconnect (PCI) compliant

◆ Preloadable output registers for testability

◆ Automatic register reset on power-up