Datasheet

AD5504 Data Sheet
Rev. B | Page 18 of 20
INTERFACING EXAMPLES
The SPI interface of the AD5504 is designed to allow it to be
easily connected to industry-standard DSPs and microcon-
trollers. Figure 19 shows how the AD5504 can be connected to
the Analog Devices, Inc., Blackfin® D S P. The Blackfin has an
integrated SPI port that can be connected directly to the SPI
pins of the AD5504. Programmable input/output pins are also
available and can be used to read or set the state of the digital
input or output pins associated with the interface.
SPISELx
ADSP-BF531
AD5504
SCK
MOSI
MISO
PF10
PF8
PF9
PF7
SYNC
SCLK
SDI
SDO
R_SEL
CLR
LDAC
ALARM
07994-016
Figure 19. Interfacing to a Blackfin DSP
The Analog Devices ADSP-21065L is a floating point DSP with
two serial ports (SPORTs). Figure 20 shows how one SPORT
can be used to control the AD5504. In this example, the transmit
frame synchronization (TFS) pin is connected to the receive
frame synchronization (RFS) pin. The transmit and receive
clocks (TCLK and RCLK) are also connected together. The user
can write to the AD5504 by writing to the transmit register. When a
read operation is performed, the data is clocked out of the AD5504
on the last 12 SCLKs. The DSP receive interrupt can be used to
indicate when the read operation is complete.
SYNC
SCLK
SDI
SDO
R_SEL
CLR
LDAC
ALARM
AD5504
ADSP-21065L
TFSx
RFSx
TCLKx
RCLKx
DTxA
DRxA
FLAG
0
FLAG
1
FLAG
2
FLAG
3
07994-017
Figure 20. Interfacing to an ADSP-21065L DSP