I/O configuration

Details	Message
Read-Only Author Ricky Tan Posted 6-Nov-2001 13:18 GMT Toolset None	I/O configuration Ricky Tan Does anybody know how to configure the 4 ports of the 8XC251SB? I need to configure ports 0,1,2 so that i get 2 output and 1 input port. Thanks

Read-Only Author tom mazowiesky Posted 6-Nov-2001 13:49 GMT Toolset None	RE: I/O configuration tom mazowiesky Well, you dont have to specifically configure them. Just as in an 8051, the ports dont have any kind of configuration registers. Any port pin that you write a 1 to, will be driven high with a weak pull up, and can therefore act as a 1 output, or an input. Any pin driven with a 0, will be an output low. The exception to this is port 0, which requires a pull up resistor to VCC on each pin, if you want to use it as an output and drive a 1 on it. Without the pull up it is an open drain output. Also, port 0 and 2 cant be used as ports if you are addressing external memory. External addressing uses port 0 and port 2 to provide the addressing (port 2 & 0) and the data bus (port 0 multiplexed). If you don't already have it, get the 8XC251SA, etc. Embedded Microcontroller Users Manual from Intel. This describes the chip and its operation in detail.

Read-Only Author Ricky Tan Posted 6-Nov-2001 15:09 GMT Toolset None	RE: I/O configuration Ricky Tan Thanks a million!! I really needed that!!! =Þ