bktan1974@netscape.net (John Tan) wrote in message news:<eb4dd21b.0402190211.6ec7d68f@posting.google.com>...
> How can we easily implement SPI using Microchip PIC16C5X series
> devices, using some GPIO. If firmware achievable to implement a
> slave/master interface.
> 
> Thanks for everyones input here....!

Look at some of the C compilers for the PICs.  At least one (CCS,
www.ccsinfo.com) has built in support for SPI master.  If the chip as
SPI hardware you can target the function for that or use just about
any combination of I/O pins.

Also look at the Microchip application notes for SPI:

http://www.microchip.com/1010/suppdoc/appnote/func/commun/spi/index.htm

Rob Young
rwyoung@ieee.org

On 19 Feb 2004 02:11:45 -0800, John Tan wrote:

>How can we easily implement SPI using Microchip PIC16C5X series
>devices, using some GPIO. If firmware achievable to implement a
>slave/master interface.

Should give you the general idea (untested):

spi_writebyte:
 movwf tmp
 movlw 8
 movwf cntr
$1
 btfss tmp,0
 bcf spi_out
 btfsc tmp,0
 bsf spi_out

 bsf spi_clk
 bcf spi_clk

 rrcf tmp
 decfsz cntr
 goto $1

 return

;-----------------

spi_readbyte:
 movlw 8
 movwf cnt
 clrf tmp
$1
 rrcf tmp

 bsf spi_clk
 btfsc spi_in
 bsf tmp,7
 bcf spi_clk

 decfsz cntr
 goto $1

 movfw tmp
 return

-- 
  Max

John Tan wrote:

> How can we easily implement SPI using Microchip PIC16C5X series
> devices, using some GPIO. If firmware achievable to implement a
> slave/master interface.
> 
> Thanks for everyones input here....!

I've implemented software SPI on the AVR '2313, with several slaved to a 
  mid-range PIC with hardware SPI as the master. It was quite easy. You 
should be able to do the same with your PIC.

Leon
-- 
Leon Heller, G1HSM
Email: aqzf13@dsl.pipex.com
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html

On 19 Feb 2004 02:11:45 -0800, bktan1974@netscape.net (John Tan) wrote:

>How can we easily implement SPI using Microchip PIC16C5X series
>devices, using some GPIO. If firmware achievable to implement a
>slave/master interface.
>
>Thanks for everyones input here....!

SPI (master) is extremely easy to do in software on any micro - just wiggle the clock line and
squirt the bits out. 

How can we easily implement SPI using Microchip PIC16C5X series
devices, using some GPIO. If firmware achievable to implement a
slave/master interface.

Thanks for everyones input here....!