...because we can't all be on the bleeding edge...





LPC SERIAL/2A

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.