User`s manual

1559B
ININININ1111
1549A
OUTINININ0111
15399
INOUTININ1011
15298
OUTOUTININ0011
14793
ININOUTIN1101
14692
OUTINOUTIN0101
14591
INOUTOUTIN1001
14490
OUTOUTOUTIN0001
1398B
INININOUT1110
1388A
OUTININOUT0110
13789
INOUTINOUT1010
13688
OUTOUTINOUT 0010
13183
ININOUTOUT1100
13082
OUTINOUTOUT0100
12981
INOUTOUTOUT1000
12880
OUTOUTOUTOUT0000
DECIMALHEX
PORT C
LOWER
PORT BPORT C
UPPER
PORT AD0D1D3D4
7.5.3 DAC PACER CLOCK DATA AND CONTROL REGISTERS
8254B COUNTER 0 DATA
- ADC PRE-TRIGGER INDEX COUNTER (or User Counter 4 when not
using Pre-trigger)
BADR3 + 8
READ/WRITE
D0D1D2D3D4D5D6D7
01324567
Counter 0 of the DAC 8254 device is used as the ADC Pre-Trigger index counter. This counter serves to
mark the boundary between pre- and post-trigger samples when the ADC is operating in Pre-Trigger Mode.
The External ADC Trigger flip flop gates Counter 0 on; the ADC FIFO Half-Full signal gates it off.
Having the desired number of post-trigger samples, software can then calculate how many 1/2 FIFO data
packets need to be collected and what corresponding residual sample count needs to be written to BADR3
+ 0.
When not using the counter for Pre-Trigger functions, it is available as User Counter 4.
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