Chapter 1
Outline Description
Page 1
Blue Chip Technology Ltd.
01270170.doc
OUTLINE DESCRIPTION
The ADC-44d is a PC-compatible short card which provides digital inputs and
outputs, timers, analogue inputs and analogue outputs.
There are 24 TTL compatible programmable digital input/outputs available
externally. There are also three programmable timers. Two of the timer outputs
are available externally to the user and may be gated by external circuitry. The
third timer acts as a prescaler to the other two.
Analogue inputs may be either sixteen single-ended or eight differential signals.
The input ranges from ±50 mVolts to ±10 Volts for a full scale reading. Input
resolution is 12 bits.
There are four analogue outputs available as ±10 Volts and 0 to +20 mA
(corresponding to a voltage output range of 0 to +10 Volts) simultaneously.
Output resolution is 12 bits.
Analogue conversions (input or output) may be made under programmed I/O
control, interrupt control or DMA control. The timers may be used to control
the rate of operation if required.
DMA data transfers for both the analogue inputs and outputs may operate
simultaneously, thereby providing a constant stream of input and output data
with little program intervention.