BUF18830EVM Software
19
SBOU103A – April 2011 – Revised May 2016
Copyright © 2011–2016, Texas Instruments Incorporated
BUF18830EVM User Guide and Software Tutorial
2.3.4
Write DAC Button
The method used to write the values in the DAC/V
COM
registers is based on whether or not the Auto Write
feature is enabled. The BUF18830 has two methods of writing information into the DAC/V
COM
registers.
The first method allows for the output voltage to change immediately after the writing to the DAC register.
In the BUF18830EVM software, this mode is configured by enabling the Auto Write feature found in the
Buffer
dropdown menu. In this mode, as an individual channel is written to, the output voltage changes as
soon as the user moves to a different text box in the software. The second method of writing to the
DAC/V
COM
registers allows for the user to write multiple channels and then have all of the output voltages
change at the same time, rather than each channel voltage changing as soon as it is written to.
Disabling the Auto Write feature in the software allows the user to enter all of the values desired for all of
the channels and then press the
Write DAC
button to change all of the output voltage of all of the
channels at one time. When the Auto Write feature is enabled, no change occurs to the output voltages
when the
Write DAC
button is pressed. No change occurs because after the text box for a given channel
has been updated, as soon as another item in the software is clicked, the Auto Write feature automatically
performs a write command to the updated channel that then updates the output voltage. When in the Auto
Write enabled mode, the
Write DAC
button cannot be pressed with different data in the corresponding
channel text boxes than the values already stored in the DAC/V
COM
register; thus, no change occurs.
shows the location in the Buffer Menu showing the Auto Write feature enabled. Clicking on the
Auto Write feature again enables/disables the feature, depending on its current state.
Figure 19. Auto Write Feature Enabled
2.3.5
Reset Button
Pressing the
Reset
button in the BUF18830EVM software performs two functions. The first function is to
call a General-Call Reset for the BUF18830. The status of the DAC/V
COM
registers after this General-Call
Reset default to
1000000000
, or mid-supply. The second function performed after the Reset button is
pressed is that a Read DAC call is made to update the corresponding channel text boxes to the current
value for each channel.
