AD9869-EBZ Analog Devices Inc, AD9869-EBZ Datasheet - Page 15

• Manufacturer Part Number: AD9869-EBZ
• Description: BOARD EVAL FOR AD9869
• Manufacturer: Analog Devices Inc
• Type: ADC + DAC, Codec, Front End for RFr

Specifications of AD9869-EBZ

• Contents: Board
• For Use With/related Products: AD9869
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 5 illustrates the timing requirements for a write opera-
tion to the SPI port. After the serial port enable ( SEN ) signal
goes low, data (SDIO) pertaining to the instruction header is
read on the rising edges of the clock (SCLK). To initiate a write
operation, the read/not-write bit is set low. After the instruction
header is read, the eight data bits pertaining to the specified
register are shifted into the SDIO pin on the rising edge of the
next eight clock cycles. If a multibyte communication cycle is
specified, the destination address is decremented (MSB first)
and shifts in another eight bits of data. This process repeats until
all the bytes specified in the instruction header (N1 bit, N0 bit)
are shifted into the SDIO pin. SEN must remain low during the
data transfer operation, only going high after the last bit is
shifted into the SDIO pin.
SCLK
SCLK
SCLK
SDIO
SDO
SDIO
SDIO
SEN
SEN
SEN
t
t
DS
DS
t
DS
t
t
t
t
t
t
HI
S
S
HI
S
HI
Figure 6. SPI 3-Wire Read Operation Timing
Figure 7. SPI 4-Wire Read Operation Timing
1/
1/
1/
R/W
R/W
R/W
t
t
f
t
f
Figure 5. SPI Write Operation Timing
f
DH
DH
SCLK
DH
SCLK
SCLK
N1
N1
t
t
t
N1
LOW
LOW
LOW
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A2
A2
N0
A1
A1
A0
A0
A0
Figure 6 illustrates the timing for a 3-wire read operation to the
SPI port. After SEN goes low, data (SDIO) pertaining to the
instruction header is read on the rising edges of SCLK. A read
operation occurs if the read/not-write indicator is set high.
After the address bits of the instruction header are read, the
eight data bits pertaining to the specified register are shifted out
of the SDIO pin on the falling edges of the next eight clock
cycles. If a multibyte communication cycle is specified in the
instruction header, a similar process as previously described for
a multibyte SPI write operation applies. The SDO pin remains
three-stated in a 3-wire read operation.
Figure 7 illustrates the timing for a 4-wire read operation to the
SPI port. The timing is similar to the 3-wire read operation with
the exception of the data appearing at the SDO pin, while the
SDIO pin remains at high impedance throughout the operation.
The SDO pin is an active output only during the data transfer
phase and remains three-stated at all other times.
t
t
DV
DV
D7
D7
D7
D6
D6
D6
D1
D1
D1
D0
D0
t
H
D0
t
t
t
EZ
EZ
EZ
AD9869