??? 02/21/06 20:39 Read: times |
#110440 - If that's true, then something's broken Responding to: ???'s previous message |
Since you can get within the required limits with 12 MHz and T2, you don't need to worry about reliability. Async starts over with each start bit. Besides, the typical 805x is a >24 MHz part nowadays, isn't it? You can get really close with that rate.
With 11-bit async, it doesn't matter how "close" you are, and it doesn't help being "closer" so long as you're within the specified limits, which will ensure that, with mid-bit sampling, the receiver will not shift enough with respect to the transmitter to cross a bit-boundary. With a start-bit, 8 data bits, parity, and a stop bit, that means 1/20 (5%) of a bit is the maximum, right? The stop bit doesn't matter, nor does its number, so there can be one or two, or more. If you have no parity or only seven bits, then the margin is wider. RE |