National Instruments 320030-01 Chapter 6 Theory of Operation

Contents
© National Instruments Corporation ix GPIB-1014 User Manual
Going from Standby to Active Controller......................................................... 5-4
Going from Active to Idle Controller................................................................ 5-5
The GPIB-1014 as GPIB Talker and Listener............................................................... 5-6
Programmed Implementation of Talker and Listener ....................................... 5-6
Addressed Implementation of the Talker and Listener ..................................... 5-6
Address Mode 1..................................................................................... 5-6
Address Mode 2..................................................................................... 5-6
Address Mode 3..................................................................................... 5-7
Sending/Receiving Messages........................................................................................ 5-8
Using Direct Memory Access ........................................................................... 5-8
DMA Transfers without the Carry Cycle.............................................. 5-10
DMA Transfers with the Carry Cycle................................................... 5-13
Polling During DMAs ........................................................................... 5-17
Sending END or EOS............................................................................ 5-17
Terminating the Transfer and Checking the Result............................... 5-17
Terminating on END or EOS................................................................ 5-19
Using Programmed I/O ..................................................................................... 5-19
Sending and Receiving Data ................................................................. 5-19
Sending END or EOS............................................................................ 5-20
Terminating on END or EOS................................................................ 5-20
Interrupts ....................................................................................................................... 5-20
Serial Polls..................................................................................................................... 5-22
Conducting a Serial Poll.................................................................................... 5-22
Responding to a Serial Poll ............................................................................... 5-22
Parallel Polls.................................................................................................................. 5-22
Conducting a Parallel Poll................................................................................. 5-23
Responding to a Parallel Poll ............................................................................ 5-24
Chapter 6
Theory of Operation.......................................................................................................... 6-1
VMEbus Interface ......................................................................................................... 6-1
Data Lines.......................................................................................................... 6-1
Slave Read and Write Transfers............................................................ 6-1
DMA Transfers...................................................................................... 6-1
Control Signals.................................................................................................. 6-2
Address.............................................................................................................. 6-2
Control Equations of Transceivers.................................................................... 6-3
Address Decoding ......................................................................................................... 6-3
Clock and Reset Circuitry ............................................................................................. 6-4
Configuration Registers................................................................................................. 6-5
Configuration Register 1 ................................................................................... 6-5
Configuration Register 2 ................................................................................... 6-6
Timing State Machine ................................................................................................... 6-6
Slave Cycles ...................................................................................................... 6-6
DMA Cycles...................................................................................................... 6-7
DMA Gating and Control.............................................................................................. 6-7
Interrupter...................................................................................................................... 6-9
DTB Requester and Controller...................................................................................... 6-9
GPIB Synchronization and Interrupt Control................................................................ 6-12