User manual

MCP4728 Evaluation Board User’s Guide
DS51837A-page 32 © 2009 Microchip Technology Inc.
1.3.2.16 EXAMPLE 9: WRITE POWER-DOWN SELECTION BITS IN DAC INPUT
REGISTER
This command writes power-down bits to the DAC input registers.
Figure 1-22 shows an example of writing a new script file for Power-Down mode.
.
FIGURE 1-22: Writing Script file to write the power-down bits. The channel outputs are updated
immediately with the ACK pulse. This command does not require UDAC
bit or LDAC pin change.
Parameters in the Script Detail column:
1. To change value:
Click this box and
type a new value
2. To delete or Insert box:
Select the box and
right click the mouse
button for options
available
3. Make sure the listed
parameters in “script
Detail” are in the exact
order as shown here.
Script Detail
I2CSTART *
I2CWRTBYT *
03 -------> This means there are three bytes to send.
C0 -------> Address byte = 1100-0000 (See Note).
AF -------> Command Type and Power-Down bits for Chs. A and B.
FF -------> Power-Down bits for Channels C and D.
I2CSTOP *
Note: All parameters above must be listed in order. The parameter above with *
are not modifiable. The MCP4728 device on the evaluation board has I
2
C
address bits (A2, A1, A0) = (0,0,0).