AD9953/PCB Analog Devices Inc, AD9953/PCB Datasheet - Page 26

• Manufacturer Part Number: AD9953/PCB
• Description: BOARD EVAL FOR AD9953
• Manufacturer: Analog Devices Inc
• Series: AgileRF™r
• Type: DDS (Direct Digital Synthesis)r

Specifications of AD9953/PCB

• Rohs Status: RoHS non-compliant
• Contents: Evaluation Board
• For Use With/related Products: AD9953

AD9953
There are two phases to a communication cycle with the
AD9953. Phase 1 is the instruction cycle, which is the writing of
an instruction byte into the AD9953, coincident with the first
eight SCLK rising edges. The instruction byte provides the
AD9953 serial port controller with information regarding the
data transfer cycle, which is Phase 2 of the communication cycle.
The Phase 1 instruction byte defines whether the upcoming data
transfer is read or write and the serial address of the register
being accessed.
The first eight SCLK rising edges of each communication cycle
are used to write the instruction byte into the AD9953. The
remaining SCLK edges are for Phase 2 of the communication
cycle. Phase 2 is the actual data transfer between
and the system controller. The number o
SCLK
SCLK
SCLK
SCLK
SDIO
SDIO
SDIO
SDIO
SDO
CS
CS
CS
CS
I
I
7
7
I
I
7
7
I
I
6
6
I
f bytes transferred
I
6
6
INSTRUCTION CYCLE
Figure 26. 2-Wire Seri al Port Read Ti
INSTRUCTION CYCLE
I
INSTRUCTION CYCLE
I
INSTRUCTION CYCLE
Figure 24. 3-Wire Serial Port Read T
5
5
I
I
5
5
Figure 25. Serial Port
Figure 23. Serial Port Write Timi
the AD9953
I
I
4
4
I
I
4
4
I
I
3
3
I
I
3
3
I
I
2
2
I
I
2
2
Rev. A | Page 26 of 32
I
I
1
1
I
I
1
1
Write Timi
I
I
0
0
I
I
0
0
D
D
O 7
ng—Clock Stall High
7
ng—Clock Stall Low
during Phase 2 of the communication cycle is a function of the
register being accessed. For example, when accessing the Control
Function Register No. 2, which is three bytes wide, Phase 2 requires
that three bytes be transferred. If accessing the frequency tuning
word, which is four bytes wide, Phase 2 requires that four bytes
be transferred. After transferring all data bytes per the
instruction, the communication cycle is completed.
At the completion of any communication cycle, the AD9953
serial port controller expects the next eight rising SCLK edges
to be the instruction byte of the next communication cycle. All
data input to the AD9953 is registered on the rising edge of
SCLK. All data is driven out of the AD9953 on the falling
of SCLK. Figure
ing the general operation of the AD9953 serial port.
iming—Clock Stall Low
D
ming—Clock Stall High
7
D
O 7
D
D
6
O 6
D
D
O 6
DATA TRANSFER CYCLE
DATA TRANSFER CYCLE
DATA TRANSFER CYCLE
DATA TRANSFER CYCLE
6
D
D
5
O 5
DON'T CARE
D
D
O 5
5
D
D
4
O 4
D
D
O 4
4
23 through Figure 26 are useful in
D
D
3
O 3
D
D
O 3
D
3
D
2
O 2
D
D
O 2
2
D
D
1
O 1
D
D
O 1
1
D
0
D
O 0
D
O 0
D
0
ed
ge