Sample Programs
Appendix C
GPIB-1014 User Manual
C-20
© National Instruments Corporation
|
| * * * * * * * * * * * * * * *
| * COMMAND - CMD *
| * * * * * * * * * * * * * * *
|
| Summary:
| - Send GPIB interface or command messages
|
| Assumptions on entry:
| - The GPIB-1014 is Controller-In-Charge
| - The commands to be sent are in cmdbuf
|
- The variable cmdct contains the number of
|
commands to be sent, which must be less than 256
|
- Interruption of any data transfer in progress is
|
acceptable
|
| Actions:
|
- Issue TCA command to assert ATN in case the
|
GPIB-1014 is at standby
| - Load the d0 register with the address of cmdbuf
|
- Load a0 with the number of commands
| - Call CSEND to transmit the bytes
|
| Status on return:
|
- GPIB-1014 is Active Controller
|
- GPIB devices are programmed as implied by
|
command bytes
|
|
68000 Code
| Comments
--------------------------------------------------------------------------------------------------------------------------------------------
|
CMD:
movb
#TCA,AUXMR
| Take control in case at standby
|
movl
#cmdbuf,a0
| Set up registers for CSEND call
movw #cmdct,d0
|
|
bsr
CSEND
| Call CSEND to send commands
|
rts
|