upon receiving a byte on its Rx pin, at what time within a bit does the USART module sample the input voltage level?
Background: In an attempt to let my ATtiny2313 communicate with a home theatre PC, I chose to connect its USART pins Rx and Tx to the main board's IrDA header. It also conveniently provides the tiny's supply voltage of +5V even when PC is powered off. That's important for the purpose of tiny. It shall wake PC at a defined time. PC defines it prior to shutting itself down. Time may be a few hours or two weeks, whenever the next scheduled recording is going to be aired.
Being an IrDA interface, PC side cuts every bit into 16 equally long slices and sets high bits only during slices 8, 9, 10. So slices 0-7, 11-15 are low no matter what. Receiver will recognize a Start Bit from its edge, which is at slice 8. But receiver doesn't know that. So for it, There are slices 0, 1, 2 set (or not) and all others are always clear.
Bytes 0x00 and 0x4C will look this:
IDLE S 0 1 2 3 4 5 6 7 T IDLE S 0 1 2 3 4 5 6 7 T IDLE
S - Start bit
T - Stop bit
So if USART module would check its Rx pin exactly in the middle of any bit, I'd reliably get zeroes. Can I get USART module to sample within the first 3/16 of any bit?