Table 2 is a matrix describing all the possible modes for the SP366 and lists the jumper settings
for each mode. The Driver inputs, SLEW, MODE and the Loop back are all define an operating
mode. The modes are listed in the first column. The inputs to T1_In (TP32 & TP44), T2_In (TP31
& TP43), T3_In (TP30 & TP42) and T4_In (TP14 & TP8) can be made using the 50 Ohm
terminated resistor. Set the SP336 for the mode to be tested. Channels can also be connected
high or low individually by the test points mention above and reference in Table 1.
Slew rate control for the SP336E drivers is logic selectable using the SLEW pin which is
connected to SW3-4 “1”. Connecting SW3-4 (Left) provides high speed and no slew limiting
while SW3-4 “0” (Right) limits the driver slew rate.
Local loop back diagnostic mode for RS232 is provided “on chip” by using logic programmable
mode 000. Local loop back testing for RS485/422 mode is also provided on the evaluation board
and can be implemented using the headers (Sw3-1 is Mode 0, SW3-2 is Mode 1 & SW3-3 is
Mode 2). Set mode input logic to 101 to define RS485/422 mode. Follow Table 4 and jumper
from test point to test point to Loopback.
Reference to Table 4:
Table 4
