COMPUTER MODULES, INC.
LPC SERIAL/2A
|
Card Type |
Serial |
|
Chip Set |
Zilog |
|
I/O Options |
Serial ports (2) |
|
Data Bus |
8-bit ISA |
|
CONNECTIONS | |||
|
Function |
Label |
Function |
Label |
|
Serial port 1 (May be RS-232, RS-422/423, or RS-485) |
J1 |
Serial port 2 (RS-232 only) |
J2 |
|
USER CONFIGURABLE SETTINGS | |||
|
Setting |
Label |
Position | |
|
Factory configured - do not alter |
SW1/1 |
Off | |
|
CLOCK SOURCE FOR PORT 1 | |
|
Setting |
JB3 |
|
External clock from serial RTxC |
Pins 1 & 2 closed |
|
Internal clock from 8254 |
Pins 1 & 3, 2 & 4 closed |
|
DMA CHANNEL - RECEIVE | |
|
Setting |
JB1 |
|
DMA1 |
Pins 9 & 10, 13 & 14 closed |
|
DMA3 |
Pins 10 & 12, 14 & 16 closed |
|
Disabled |
Above pins open |
|
DMA CHANNEL - TRANSMIT | |
|
Setting |
JB1 |
|
DMA1 |
Pins 9 & 11, 13 & 15 closed |
|
DMA3 |
Pins 11 & 12, 15 & 16 closed |
|
Disabled |
Above pins open |
|
Note: If a DMA is used for transmission then port 1 may not be used. | |
|
BASE I/O ADDRESS | ||||||||
|
Setting |
SW1/2 |
SW1/3 |
SW1/4 |
SW1/5 |
SW1/6 |
SW1/7 |
SW1/8 | |
|
000h |
On |
On |
On |
On |
On |
On |
On | |
|
008h |
On |
On |
On |
On |
On |
On |
Off | |
|
010h |
On |
On |
On |
On |
On |
Off |
On | |
|
018h |
On |
On |
On |
On |
On |
Off |
Off | |
|
020h |
On |
On |
On |
On |
Off |
On |
On | |
|
380h |
Off |
Off |
Off |
On |
On |
On |
On | |
|
3D8h |
Off |
Off |
Off |
Off |
On |
Off |
Off | |
|
3E0h |
Off |
Off |
Off |
Off |
Off |
On |
On | |
|
3E8h |
Off |
Off |
Off |
Off |
Off |
On |
Off | |
|
3F0h |
Off |
Off |
Off |
Off |
Off |
Off |
On | |
|
3F8h |
Off |
Off |
Off |
Off |
Off |
Off |
Off | |
|
Note: A total of 127 base address settings are available. The switches are a binary representation of the decimal memory addresses. SW1/2 is the Most Significant Bit and switch SW1/8 is the Least Significant Bit. The switches have the following decimal values: SW1/8=8, SW1/7=16, SW1/6=32, SW1/5=64, SW1/4=128, SW1/3=256, SW1/2=512. Turn off the switches and add the values of the switches that are off to obtain the correct memory address. (Off=1, On=0) | ||||||||
|
INTERRUPT | |
|
Setting |
JB1 |
|
IRQ3 internally |
Pins 1 & 2 closed |
|
IRQ3 from 8254 |
Pins 1 & 3 closed |
|
IRQ4 internally |
Pins 2 & 4 closed |
|
IRQ4 from 8254 |
Pins 3 & 4 closed |
|
IRQ5 internally |
Pins 5 & 6 closed |
|
IRQ5 from 8254 |
Pins 5 & 7 closed |
|
IRQ7 internally |
Pins 6 & 8 closed |
|
IRQ7 from 8254 |
Pins 7 & 8 closed |
|
PORT 1 TYPE | |||||
|
Setting |
JB4 |
U5 |
U6 |
U9 |
U10 |
|
RS-232 |
Pins 1 & 2, 4 & 5 open |
Not installed |
MC1489 |
Not installed |
MC1488 |
|
RS-422/423 |
Pins 1 & 2, 4 & 5 open |
26LS32 |
Not installed |
26LS31 |
Not installed |
|
RS-485 |
Pins 1 & 2, 4 & 5 closed |
26LS32 |
Not installed |
26LS31 |
Not installed |
|
PORT 1 PINS 9 & 10 | |
|
Setting |
JB3 |
|
+12V DC |
Pins 7 & 8 closed |
|
Not used |
Pins 7 & 8 open |
|
PORT 1 RS-422/423/485 DRIVER | |
|
Setting |
JB3 |
|
Enabled by RTS |
Pins 5 & 6 closed |
|
Enabled permanently |
Pins 3 & 5 closed |
|
PORT 1 RS-422/423 DRIVER TERMINATION | |||
|
Setting |
JB4 |
RP3 |
RP4 |
|
Not terminated |
Pins 5 & 6, 7 & 8 closed |
Not installed |
Not installed |
|
Terminated |
Pins 5 & 7, 6 & 8 closed |
Installed |
Installed |
|
Note: The ohm values of RP3 and RP4 should be determined to cause a difference in voltage of at least 2.0V between the ends of the serial cable. | |||
|
8254 CLK0 SOURCE | |
|
Setting |
JB2 |
|
8254 clock signal |
Pins 15 & 16 closed |
|
Disabled |
Pins 15 & 16 open |
|
8254 CLK1 SOURCE | |
|
Setting |
JB2 |
|
8254 clock signal |
Pins 13 & 14 closed |
|
8254 CLK0 |
Pins 11 & 13 closed |
|
Disabled |
Above pins open |
|
8254 CLK2 SOURCE | |
|
Setting |
JB2 |
|
8254 clock signal |
Pins 10 & 12 closed |
|
8254 CLK1 |
Pins 9 & 10 closed |
|
Disabled |
Above pins open |
|
CLK0 INTERRUPT GENERATOR | |
|
Setting |
JB2 |
|
CLK0 generates interrupt |
Pins 7 & 8 closed |
|
CLK0 does not generate interrupt |
Pins 7 & 8 open |
|
CLK1 INTERRUPT GENERATOR | |
|
Setting |
JB2 |
|
CLK1 generates interrupt |
Pins 5 & 6 closed |
|
CLK1 does not generate interrupt |
Pins 4 & 6 open |
|
CLK2 INTERRUPT GENERATOR | |
|
Setting |
JB2 |
|
CLK2 generates interrupt |
Pins 1 & 3 closed |
|
CLK2 does not generate interrupt |
Pins 1 & 2 open |
|
MISCELLANEOUS TECHNICAL NOTE |
|
When using RS-422, resistors R2, R3, R5, and R6 must be installed to match the impedance of the cable that is used. The board will not function properly in RS-422 mode without these resistors. |