Rainbow Electronics MAX550A - Manual (Page 11)

MAX548A/MAX549A/MAX550A
+2.5V to +5.5V, Low-Power, Single/Dual,
8-Bit Voltage-Output DACs in µMAX Package
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Table 3. MAX549A Serial-Interface Programming Commands
DATA BYTE
UNASSIGNED COMMAND
X X
X
X X
0 X
1
0
X
X
0
0
0
1
X 0 X 0 X 1 0
XXXXXXXX
8-Bit DAC Data
Loaded First
Update both DAC registers with current contents of their
input registers. Both input registers unchanged.
Load DAC A input register. DAC registers unchanged. X
X 0 X 1 X 0 1
X 0 X 1 X 1 0
8-Bit DAC Data
Load DAC A input register and update both DAC
registers. DAC B input register unchanged.
X 1 X 0
X
X 0 1
X 1 X 0 X 1 0
8-Bit DAC Data
Load DAC A input register and power down DAC A.
DAC B input register and both DAC registers unchanged.
X
8-Bit DAC Data
Load DAC B input register and power down DAC B.
DAC A input register and both DAC registers unchanged.
X
Loaded Last
X 1 X 0 X 1 1 8-Bit DAC Data
Load both DAC input registers and power down both
DACs. Both DAC registers unchanged.
X
8-Bit DAC Data Load DAC B input register. DAC registers unchanged. X
X 0 X 0 X 1 1 8-Bit DAC Data
Load both DAC input registers. DAC registers
unchanged.
X
8-Bit DAC Data
Load DAC B input register and update both DAC
registers. DAC A input register unchanged.
X
X 0 X 1 X 1 1 8-Bit DAC Data
Load both DAC input registers and update both DAC
registers.
X
COMMAND
(Commands executed on
CS
’s rising edge)
CONTROL BYTE
UB2 C2 UB3 C1 C0 A1 A0 D7........D0 UB1
X X X 0 X 0 0 XXXXXXXX Unassigned command X
COMMANDS LOADING INPUT REGISTER(S) ONLY
COMMANDS UPDATING DAC REGISTER(S)
COMMANDS POWERING DOWN AND LOADING INPUT REGISTER(S) ONLY
X = Don’t care
COMMANDS POWERING DOWN AND UPDATING DAC REGISTER(S)
X 1 X 1 X 0 1 8-Bit DAC Data
Load DAC A input register, power down DAC A, and
update both DAC registers. DAC B input register
unchanged.
X
X 1 X 1 X 1 0 8-Bit DAC Data
Load DAC B input register, power down DAC B, and
update both DAC registers. DAC A input register
unchanged.
X
X 1 X 1 X 1 1 8-Bit DAC Data
Load both DAC input registers, power down both DACs,
and update both DAC registers.
X