Contents
Lab-NB User Manual vi © National Instruments Corporation
Chapter 3
Theory of Operation...........................................................................................................3-1
Functional Overview......................................................................................................3-1
NuBus Interface Circuitry..............................................................................................3-2
Analog Input and DAQ Circuitry...................................................................................3-3
Analog Input Circuitry.......................................................................................3-4
DAQ Timing Circuitry.......................................................................................3-4
Single-Channel Data Acquisition...........................................................3-5
Multichannel (Scanned) Data Acquisition.............................................3-5
DAQ Rates.............................................................................................3-6
Analog Output Circuitry................................................................................................3-7
Digital I/O Circuitry.......................................................................................................3-9
Timing I/O Circuitry......................................................................................................3-10
Chapter 4
Register-Level Programming.........................................................................................4-1
Register Access..............................................................................................................4-1
Slot Address Space.............................................................................................4-1
Register Map......................................................................................................4-2
Register Sizes.....................................................................................................4-4
Register Descriptions.....................................................................................................4-4
Register Description Format..............................................................................4-4
Analog Input Register Group.............................................................................4-5
A/D Configuration Register...................................................................4-6
Status Register........................................................................................4-9
A/D FIFO Register.................................................................................4-10
A/D Clear Register.................................................................................4-12
Analog Output Register Group..........................................................................4-13
DAC Configuration Register.................................................................4-14
DAC0 and DAC1 Data Registers...........................................................4-15
8253 Counter/Timer Register Groups................................................................4-16
Counter A0 Data Register......................................................................4-17
Counter A1 Data Register......................................................................4-18
Counter A2 Data Register......................................................................4-19
Counter A Mode Register......................................................................4-20
Counter B0 Data Register......................................................................4-21
Counter B1 Data Register......................................................................4-22
Counter B2 Data Register......................................................................4-23
Counter B Mode Register......................................................................4-24
82C55A Digital I/O Register Group..................................................................4-25
Port A Register.......................................................................................4-26
Port B Register.......................................................................................4-27
Port C Register.......................................................................................4-28
Digital Control Register.........................................................................4-29
Interrupt Control Register Group.......................................................................4-30
Interrupt Control Register......................................................................4-31
Interrupt Status Register.........................................................................4-33
Timer Interrupt Clear Register...............................................................4-34
Configuration EPROM..................................................................................................4-35