Datasheet

Data Sheet AD9835
Rev. A | Page 19 of 28
DATA WRITE
DEFERRED TRANSFER WRITE
WRITE 8 BITS TO DEFER REGISTER
DIRECT TRANSFER WRITE
WRITE PRESENT 8 BITS AND 8 BITS IN
DEFER REGISTER TO DATA REGISTER
WRITE ANOTHER WORD TO THIS
REGISTER?
WRITE A WORD TO ANOTHER REGISTER
CHANGE
8 BITS ONLY
YES
NO
CHANGE 16 BITS
NO
YES
09630-026
Figure 24. Data Writes
SELECT DATA SOURCES
FSELECT/PSEL PINS BEING USED?
YES
SELSRC = 0
SET PINS
SET FSELECT
SET PSEL0
SET PSEL1
FREQUENCY/PHASE REGISTER WRITE
SET FSELECT
SET PSEL0
SET PSEL1
NO
SELSRC = 1
09630-027
Figure 25. Selecting Data Sources