Xycom XVME-560 Manual page 38

XVME-560 Manual
September, 1984
3.7.4 External Trigger
The External Trigger mode will allow a low going pulse on pin 50 of connector
start a conversion. Figure 3-5 below shows the timing constraints.
An alternate method would be to have the trigger line be normally low, then pulsed
high and back Iow again as shown in Figure 3-6. This is not the preferred method since
a conversion is started when the external trigger line is disabled after previously being
enabied.
Rising edge
triggers
conversion
Procedure
1)
Connect the External Trigger signal to pin 50 of JK2.
Write the control word (base+81H) specifying mode bits
2)
3) Specify the channel and gain by writing to the Channel/Gain register.
3.8 INTERRUPTS
The AIN can generate an interrupt to notify the host that the A/D conversion is
complete and that the data is valid. The level and vector generated by this interrupt
are both user-selectable.
The following four steps must be performed to generate an interrupt:
Mode
Figure 3-5. External Trigger Pulse
Figure 3-6. Alternate External Trigger Pulse
100 nsec.
minimum
Rising edge
triggers
conversion
Ml
and MO as 1 and 1.
JK2
to