I am using the RXD & TXD of the '51 to communicate with 232 and now i want to use the second port of the 232. How do i go abt doin it since i have exhausted my RXD and TXD. Please Help. ajay
Ajay, You have to purchase a C51 variant that has two UARTs included. These chips will have multiple RxD and TxD pins. Another much-less-attractive option would be to purchase a stand-alone UART to connect to your chip to provide a second port. This would be more complicated and also cost more than another 8051-based chip WITH two UARTs, so you should make sure you have a good reason before selecting this option.
Jay Daniel thanks for the suggestion i will check out the C51 variant, i did not know abt the same tahnks again