Logic Analyzer in Miniature Size

Overview

This simple mini logic analyzer was designed with a hardware, software, and firmware interface which will buffer the signals sent from the parallel port of the computer to the circuit board for testing.

Explanation

A programmable CPLD XC95288XL device is the heart of the mini logic analyzer which uses fast synchronous SRAM AS7C33128 for storing samples. A 3.3V stabilized by LD1117DT is used to supply the devices. The CPLD contains a clock source from the oscillator which is also supplied with 3.3V although they are designed for 5V source. Old PC boards are good source for oscillators.

The source codes and documentation are released under GNU GPL and the communication is through LPT port or USB. The system has external trigger input and programmable trigger-events counter. Also, an external clock input is included along with 128Kb memory for each channel. Up to 32 channels are supported with a sampling rate of up to 100MHz. The input levels are compatible with 3.3V and 5V logic.

The free development tools are provided by the producer of CPLD  as the firmware is written in VHDL. The types of firmware include time analysis, state analysis, and LED tester.