forums.ps2dev.org

bashir0505 · Joined: 27 Dec 2005 Posts: 2 Location: Saskatoon, Canada

Hey. I need to interface the PSX controller to the 8051 microcontroller. I got alot of info about the controller from
http://www.gamesx.com/controldata/psxcont/psxcont.htm
Does anyone know what the baud rate for the "Command" and "Data" lines of the PSX controllers is?
Thanks.

J.F. · Joined: 22 Feb 2004 Posts: 2906

It's nominally 250 Kbaud. The PS2 can also communicate with PS2 controllers at twice that rate.

bashir0505 · Joined: 27 Dec 2005 Posts: 2 Location: Saskatoon, Canada

Yeah, 250kbaud, that's crazy fast. The 8051 is not capable of running at such high baud rates. Do you think if I clocked the controller at a lower frequency, I can decrease the baud rate to that frequency? Like Decreasing the clock speed to 19200Hz to get data at 19200baud, which the micro can handle.

J.F. · Joined: 22 Feb 2004 Posts: 2906

Depends on the controller. Some controllers will clock to anything you want, up to the max the hardware can handle. Some need to be rather close to 250 Kbaud or they simply ignore it. You just have to try it with the controller you have and see if it works or not.

You have to remember, the PSX/PS2 controller port is designed to be more like an SPI or I2C channel than a normal serial port. They run synchronous to a data clock at a high rate. Regular serial ports run at a low frequency because they run without a data clock and rely on start and stop bits for framing. The PSX/PS2 controller port doesn't do that.