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Synchronous Serial Port of LPC213x - is it useful for PS/2 keyboard/mouse interface

Started by Yuri Ostry December 20, 2005
Hello,

Just a stupid question from someone who still not digged up through
all those huge pile of datasheets and other documentation... 8-)

Is it possible to use SSP peripherial of LPC213x for PS/2
keyboard/mouse interface? I now trying to figure this out, reading LPC
user manual and all information that I found about PS/2 protocol, but
maybe someone already figured out that something make them completely
incompatible?

--
Sincerely,
Yuri mailto:yuri@yuri...


An Engineer's Guide to the LPC2100 Series

Yuri Ostry wrote:

>Hello,
>
>Just a stupid question from someone who still not digged up through
>all those huge pile of datasheets and other documentation... 8-)
>
>Is it possible to use SSP peripherial of LPC213x for PS/2
>keyboard/mouse interface? I now trying to figure this out, reading LPC
>user manual and all information that I found about PS/2 protocol, but
>maybe someone already figured out that something make them completely
>incompatible? >
Keep digging into the data on the keyboard protocol. You'll find that
it is a synchronis protocol where the keyboard is the clock generator.
The clock line is also used as a CTS line. IIRC, it is an 11bit
transfer. It's been many years since I did anything with the keyboard,
the signals for PS/2 keyboards are identical with AT Keyboards. XT
keyboards were something entirely different, they were simple uarts.
The later keybaords are intelligent and have a handshake protocol.

There is always bit-banging of the LPC port pins... That was the
solution I used on the 8042 controller. TomW --
Tom Walsh - WN3L - Embedded Systems Consultant
http://openhardware.net, http://cyberiansoftware.com
"Windows? No thanks, I have work to do..."
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