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FFT for FPGA, 在FPGA 上实现FFT变化 ，VHD语言

Fast routines to do mixed radix-4/5 DIF FFTs. Supported sizes include 20, 64 and 80 complex points. Optimized for ARM. If possible compile with -fomit-frame-pointer , as this gives the compiler another register to work with.

e_factory is designed to automate a factory floor with automatic process control, data collection and graphing. It is designed to be configurable to the available equipment and to be networked. Capabilities for current version are limited to RF gain, power and transfer curve measurements. Graphing and file IO are included. XForms, GPIB (LLP) and PLPLOT are required. Temperature controller is new goal.

Begin3 Title: danalyser Version: 0.2 Entered-date: 30 July 1997 Description: Digital Logic Analyzer. Reads values from selected input Description: port and displays the bits using a nice GUI and display Description: similar to a Digital Logic Analyzer.

Scope 1.0 for Linux ELF ======================= This is an oscilloscope program written in c using the XForms library. It uses the PC's parallel port for data input. The way it's done is as follows: first data bit 1 is set to 1 then to 0 to enable the a-to-d converter ( ADC0801 ), then we read 4 bits of data from the multiplexer ( 74LS157 ) placed after the a-to-d, then a 1 is sent to the second data bit and the other four bits of data are read. The circuit is setup as follows: ---------------------------------------------------------<---- Data bit 1 | | ---------------- -------------- | | D0|-------->----------| Select|----<---- Data bit 2 |---|Enable D1|-------->----------| | From | D2|-------->----------| O0|---->---- Status bit 4 Circuit->--|Ain D3|-------->----------| O1|---->---- Status bit 5 | D4|-------->----------| O2|---->---- Status bit 6 From | D5|-------->----------| O3|---->---- Status bit 7 555 timer->|CLK D6|-------->----------| | | D7|-------->----------| | ---------------- -------------- ADC0801 74LS157 The parallel port used as default is 0x378 but it can be changed within the program. Other options such as number of points per screen update and a few more can also be set from the options dialog. The 555 timer is an easy chip to configure. Set it to between 70 and 100kHz. You will need the data-sheets for these 3 chips; these can be found at www.national.com in pdf format. One thing I haven't been able to figure out yet is the frequency response of this setup. If anyone can help me with that it would be greatly appreciated. Amplitude sensitivity is approximately 0.04 volts per bit change. Also, because this program accesses the hardware directly, you will need to run it as root ( pretty obvious ). If you have any questions regarding the circuit setup or operation just let me know through e-mail and I'll write back with the solution.