A Digital Pattern Generator (or Digital Signal Generator) is a piece of electronic equipment that is capable of generating 'digital logic signals'. Such signals' are a specific kind of electrical waveform varying between two conventional levels that correspond to two logic states ('low state' and 'high state', '0' and '1'). These levels are often voltage levels.

Signal generators are the natural companion of oscilloscopes, logic analyzers and other types of analysis tools. Testing a system always requires a stimulus-and-response setup.

The primary use of a DPG is to provide a source of input stimulus for electronic devices such as ASIC, SoC, FPGA and board systems.

The output of a DPG is usually compliant with common I/O voltage standards such as TTL, LVTTL, LCMOS or LVDS, for instance. Strictly speaking, a digital pattern generator is used for its ability to generate 'data' - that is, for the logical information conveyed in its output signal - and its ability to do this synchronously - at an arbitrarily defined frequency.

The following devices from Byte Paradigm can be used as Digital Signal Generator (or DPG):

(*) GP Series are multi-function devices which include logic analyze, SPI and I²C modes of operation in addition to digital pattern generator (ADWG) mode of operation.

(**) SPI Storm features a 8-bit'GPO' ('General-Purpose Output') that can be optionally synchronized with its serial port to extend the range of custom serial protocol that can be supported with this device. 

Read more

Many instruments available on the market today show characteristics close or similar to these of digital pattern generators. However, there is a lot of confusion about the words used to designate such an equipment. Download the following table for an overview (PDF)
Wave Gen Xpress data sheet
The Digital Pattern Generator - an essential instrument ... - white paper
Engineers increasingly vote for prototyping for embedded system debug - analysis