CPLD / FPGA

Complex Programmable Logic Devices (CPLD) are programmable logic circuits defined in digital technology. They are the technological successors of the Programmable Array Logic (PAL) and their structure is simpler than that of the significantly more complex Field Programmable Gate Arrays (FPGAs). However, the programming is identical.

Fundamentals of FPGAs and CPLD

A field programmable gate array (FPGA), also called a programmable logic gate, is an integrated circuit of digital technology, in which a logic circuit can be loaded.

The classic programming of ICs or memories differs from the "programming" of FPGAs, which is actually the creation of the circuit structure of an FPGA. This is formulated using a hardware description language (VDHL / Verilog) and translated into a configuration file using logic synthesis, which specifies how the physical elements in the FPGA should be interconnected.

Creation of FPGA Designs

There are suitable solutions for creating and simulating FPGA designs, e.g. Active HDL or Rivera Pro. In addition to graphical input (block and FSM), Active HDL also includes a text editor and the powerful ALDEC simulation environment, which supports all common languages ​​for HDL development. In addition, prototyping boards are used for the development.

The logic switches and memories in most FPGAs are realized by SRAM memory cells, which are loaded appropriately during the boot process. This configuration data or link rules are usually loaded from a special Flash ROM module. A microcontroller can also be used. Most FPGAs therefore offer several modes for this configuration process (serial, parallel, master / slave). Since the SRAM cells lose their content when the supply voltage is switched off, an SRAM-based FPGA must be reconfigured each time it is switched on. Such an FPGA therefore takes a few milliseconds to a few seconds before it is fully operational. FPGAs with non-volatile memory are based on EEPROM, flash memory.
With the programmers we offer, it is possible to program all common FPGAs and CPLDs on the market.