Title: Advanced Features of NT960 Universal Firmware
Date: September 3, 1998
This applies to the NT960 Universal firmware, which is used for WinNT & QNX4.
1. RX threshold, sets the threshold at which the UART will generate a receive interrupt, allowable values are 0 to 12. Zero (firmware default) has special meaning. The RX threshold will be set according to the baud rate setting as follows:
<=76800 6 >76800 5
Setting the RX threshold to 1 gives the shortest reaction time (latency) to
2. TX load (default 12, range 1 to 12) sets the number of characters that are loaded into the transmitter each time it goes empty. This option slightly effects the amount of time spent in the TX interrupt handler. It might make a small effect on the RX latency (i.e.: lowering the TC load may decrease the RX latency).
3. RX timeout (default 5mS, range 5 to 1275mS) changes the time the receiver takes to respond to RX characters WHEN the number of characters is BELOW the RX threshold. This can be set in 5mS increments. A higher setting improves the overall throughput, by allowing the receiver to fill up to the threshold more often, but at the expense of longer latency for single characters. If the RX threshold is set to 1, the RX timeout is meaningless.
End of KDB-232