6, logic design technologies ISP

Early in the LED display screen electronic control circuit, using a large number of conventional digital circuit system design, digital circuit with a combination of complex control logic. In the conventional system Digital circuit design, circuit design is completed, subject to the production of circuit boards and components to install, debug. If the board does not meet the requirements of logic functions must be re-designed circuit board, and then re-debugging, until the realization of logic functions so far. It is clear that this design approach the design of a long cycle, high cost and poor product reliability and maintenance problems. Common use of programmable logic devices, although able to reduce printed circuit board design and production, but to amend the logic devices when they still could not avoid the plug again.

In-system programmable technology (In-System Programmable, the acronym ISP), refers to the user's own design of the target system or circuit board for the reconstruction of programming logic devices or repeatedly rewritten. Conventional PLD in use is usually after the first assembly program, and the ISP using PLD technology is the first assembly after the program has become the product can also be repeated after the program. In-system programmable technology, from the practical realization of a dream logic designers over the years the "hardware design and software revision" of the desire to make digital system on a new look. ISP use of technology, like software, hardware design has become as easy changes to hardware functions can be modified at any time or change process scheduled configured. This is not only to expand the use of the device, the system reduces the debugging cycle, and the eradication of the devices on separate aspects of the program, save the device programming equipment, the goal of simplifying the on-site equipment maintenance and upgrade work. ISP technology and a system characterized by the use of design software for the importation of logic, and the selected input device has nothing to do. As a result, the choice of input before any of the devices, and even have the option of a "virtual device" (Virtual Device). After the input, according to the results of the simulation and adaptive devices to choose.

LATTICE devices ISPLSI the United States in 1992, the company introduced a new generation of high-density programmable logic devices, with a capacity of up to 25,000, with a field programmable gate array (FPGA) capacity and flexibility. It E2CMOS process, the clock frequency up to 180MHz, for the transmission delay 5ns, low-power, electricity and erase, program content is not lost for 20 years, 100% testing parameters can be encrypted. Device has an internal resistance "lock" the circuit to prevent the emergence of CMOS devices in the possible harmful effects of the lock.


Reference link: http://www.17led.com/LEDdisplay/2008-04/48p7.html