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National Semiconductor
DAC161P997EVAL User’s Guide
2011 National Semiconductor Corporation Page 9 of 11 Rev: 0.00
“DAC161P997 Data” Tab
Click on and type in the “Loop Current (mA)” the desired current magnitude to be produced by
DAC161P997 output. Then press green SEND button. Observe the current….
Details for later:
Control
Description of Functionality
ACK
Check this box to insert and ACK symbol in the SWIF data stream
Send
Sends the data representing the output current magnitude to SWIF data buffer on
SPIO4, and activates the link to DAC161P997
Send File
Click this control to select a file as the source of SWIF data. SWIF data file is a text file
containing only ‘0’, ‘1’, ‘A’ or ‘D’ characters (representing valid SWIF symbols). It is up
to the user to format the data frames. When file is read-in the name of the file will
appear above “Send File” button and the “Loop Current” entry box will be cleared.
Stop
Stops SWIF activity
Check ACK, NACK
SPIO4 monitors the number of A symbols issued by the SWIF. Each symbol issued
increments the ACK count.
The number of responses from the DAC161P997 is also being monitored: for every A
issued by SWIF
the lack of response
from DAC161P997 increments the NACK count.
Both counters are cleared by STOP followed by SEND