JAJSQA4I march 1994 – march 2021 TL16C550C
PRODUCTION DATA
Auto-RTS data flow control originates in the receiver timing and control block (see Section 7.6) and is linked to the programmed receiver FIFO trigger level. When the receiver FIFO level reaches a trigger level of 1, 4, or 8 (see Figure 7-3), RTS is deasserted. With trigger levels of 1, 4, and 8, the sending ACE may send an additional byte after the trigger level is reached (assuming the sending ACE has another byte to send) because it may not recognize the deassertion of RTS until after it has begun sending the additional byte. RTS is automatically reasserted once the RCV FIFO is emptied by reading the receiver buffer register.
When the trigger level is 14 (see Figure 4), RTS is deasserted after the first data bit of the 16th character is present on the SIN line. RTS is reasserted when the RCV FIFO has at least one available byte space.