| ??? 03/06/07 18:14 Read: times |
#134399 - Some answers Responding to: ???'s previous message |
1. How does a Pin 3.1 which is also called as TxD differs from other port if i want to use it to transfer a series of bytes data out from the serial port to let's say a modem? Pin 3.1 is shared between port 3 and the UART TxD. Keep port bit 3.1 = 1 at all times, and it will work. 2. If i am to use ASM to send out a byte of data out from the TxD (P3.1) to a modem.For e.g : i want to send the character "A" to a modem, does the command needed to be sent this looks like this?
MOV SBUF, #A Close. The command should be mov sbuf, #'A'What you did was load sbuf with the address of the accumulator (0e0h) Can i use the similiar line:
MOV SBUF, #ATD1234567 ? No, no, no, no. The move instruction only works on one byte at a time. You will need to put your data in a buffer, and create a loop that will fetch one byte at a time and send it. 4. What would be the appropriate baud value suitable to be configured (TH1) to be used with a modem? Not enough information. We need your oscillator frequency, and the desired baud rate. And, you are better off using timer 2's baud rate capability. |
