Pcmcia I/O Channel Interface Circuitry; Figure 4-2. Pcmcia I/O Interface Circuitry Block Diagram - National Instruments Corporation DAQCard-500 User Manual

Theory of Operation
The following are the major components making up the DAQCard-500:
•

PCMCIA I/O channel interface circuitry

• Analog input circuitry
• Digital I/O circuitry
• Timing I/O circuitry
You can execute data acquisition functions by using the analog input circuitry and some of the
timing I/O circuitry. The internal data and control buses interconnect the components. The
theory of operation for each of these components is explained in the remainder of this chapter.
The theory of operation for the data acquisition circuitry is included with the discussion of the
analog input circuitry.
PCMCIA I/O Channel Interface Circuitry
The PCMCIA I/O channel interface circuitry consists of an address bus, a data bus, interrupt
lines, and several control and support signals. The components making up the DAQCard-500
PCMCIA I/O channel interface circuitry are shown in Figure 4-2.
Address Bus
Control Lines
Data Bus
IRQ

Figure 4-2. PCMCIA I/O Interface Circuitry Block Diagram

DAQCard-500 User Manual
Timing
Interface
Data
Buffers
Interrupt
Control
4-2
Address
Register Selects
Decoder
Timing Signals
Card
Information
Structure
Internal Data Bus
PCMCIA
Control
Registers
Interrupt Requests
© National Instruments Corporation
Chapter 4