EVAL-AD7923CBZ View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
'EVAL-AD7923CBZ' PDF : 24 Pages View PDF
AD7923
CS
t2
t6
tCONVERT
SCLK
1
2
3
4
5
6
t3
t4
t7
DOUT
ZERO ADD1 ADD0 DB11
THREE-
2 IDENTIFICATION
STATE ZERO
t9
BITS
DIN
WRITE SEQ1 DONTC DONTC ADD1
DB10
t10
ADD0
11
12
B
13
14
t5
DB4
DB3
DB2
DB1
15
16
t8
DB0
t11
tQUIET
THREE-
STATE
CODING DONTC DONTC DONTC DONTC
Figure 27. Serial Interface Timing Diagram
CS
1
16
SCLK
tCYCLE 5s MIN
1
16
tQUIET MIN
1
16
DOUT
VALID DATA
VALID DATA
DIN
POWER-UP
Figure 28. General Timing Diagram
MICROPROCESSOR INTERFACING
The serial interface on the AD7923 allows the part to be directly
connected to a range of many different microprocessors. This
section explains how to interface the AD7923 with some of the
more common microcontroller and DSP serial interface protocols.
AD7923-to-TMS320C541
The serial interface on the TMS320C541 uses a continuous
serial clock and frame synchronization signals to synchronize
the data transfer operations with peripheral devices like the
AD7923. The CS input allows easy interfacing between the
TMS320C541 and the AD7923 without any glue logic required.
The serial port of the TMS320C541 is set up to operate in burst
mode with internal CLKX0 (Tx serial clock on Serial Port 0)
and FSX0 (Tx frame sync from Serial Port 0). The serial port
control register (SPC) must have the following setup: FO = 0,
FSM = 1, MCM = 1, and TXM = 1. The connection diagram is
shown in Figure 29. It should be noted that for signal processing
applications, it is imperative that the frame synchronization
signal from the TMS320C541 provides equidistant sampling.
The VDRIVE pin of the AD7923 takes the same supply voltage as
the TMS320C541. This allows the ADC to operate at a higher
voltage than the serial interface, that is, the TMS320C541, if
necessary.
AD79231
SCLK
DOUT
DIN
CS
VDRIVE
TMS320C5411
CLKX
CLKR
DR
DT
FSX
FSR
1 ADDITIONAL PINS REMOVED FOR CLARITY.
VDD
Figure 29. Interfacing to the TMS320C541
AD7923-to-ADSP-21xx
The ADSP-21xx family of DSPs is interfaced directly to the
AD7923 without any glue logic required. The VDRIVE pin of the
AD7923 takes the same supply voltage as the ADSP-218x,
which allows the ADC to operate at a higher voltage than the
serial interface, that is, ADSP-218x, if necessary.
The SPORT0 control register should be set up as follows:
TFSW = RFSW = 1, alternate framing
INVRFS = INVTFS = 1, active low frame signal
DTYPE = 00, right justify data
SLEN = 1111, 16-bit data-words
ISCLK = 1, internal serial clock
TFSR = RFSR = 1, frame every word
IRFS = 0
ITFS = 1
Rev. C | Page 21 of 24
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