HOW CAN I DESING AN ALU?

Have you looked at the 74181 datasheet? I found this amusing

I'm having trouble with the "most little parts" part of that. Do you mean:

(A) A low number of parts of any kind.

(B) A low number of small parts.

(C) It must use diodes and transistors and not complete ICs and keep the number of them low.

For (A) I'd suggest a CPLD programmed to be an ALU.

For (B) I'd suggest the 74HC181 (IIRC)

For (C) I'd suggest finding out what you can but the cheapest first.

Then you first have to specify the requirements. Minimum parts are achieved with minimum bit-width, in this case 2 bits, and by having a minimum number of operations, here add & sub, that makes an operation selector with one bit.

Rene

Si usted necesita esta mucha ayuda en este tiempo en sus clases, usted no ha estado aprendiendo claramente las lecciones. Él si todos están en sus libros de textos y notas de la conferencia. Un subtractor es simplemente una serpiente[1] con una inversión del dos-complemento del subtrahend. End-around lleve, por supuesto, es opcional. ¿Cómo difícilmente puede estar?

Buena Suerte! Rich

DooD! They're doing a barrel shifter in 7408's! Geez, why not ask the guy to build a PDP-11?

;-P

Cheers! Rich

Try this: "VHDL for Programmable Logic" written by Kevin Skahill of Cypress Semiconductor pages 293- 326 A case of the 2901 bit slice chip

Good luck, Dave

I would base you ALU on an FPGA, e.g. Xilinx, Altera or Lattice. For code examples in Verilog and VHDL, take a look at ...

There are several CPU designs and most if (not all) are GPL :-)

Mike.

thank you, but 74HC181 is an 4-bits ALU, but I need a 2-bit ALU can you help me? Andrew Holme ha escrito:

Off the top of my head...

A two-bits won't cut it these days.

-- Keith

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