Datasheet

Data Sheet AD5383
Rev. C | Page 31 of 40
MICROPROCESSOR INTERFACING
Parallel Interface
The AD5383 can be interfaced to a variety of 16-bit microcon-
trollers or DSP processors. Figure 35 shows the AD5383 family
interfaced to a generic 16-bit microcontroller/DSP processor. The
lower address lines from the processor are connected to A0 to
A4 on the AD5383. The upper address lines are decoded to
provide a
CS
,
LDAC
signal for the AD5383. The fast interface
timing of the AD5383 allows direct interface to a wide variety of
microcontrollers and DSPs, as shown in
Figure 35.
AD5383 to MC68HC11
The serial peripheral interface (SPI) on the MC68HC11 is
configured for master mode (MSTR = 1), the clock polarity bit
(CPOL) = 0, and the clock phase bit (CPHA) = 1. The SPI is
configured by writing to the SPI control register (SPCR)—see
the 68HC11 User Manual. SCK of the 68HC11 drives the SCLK
of the AD5383, the MOSI output drives the serial data line
(DIN) of the AD5383, and the MISO input is driven from
DOUT. The
SYNC
signal is derived from a port line (PC7).
When data is being transmitted to the AD5383, the
SYNC
line
is taken low (PC7). Data appearing on the MOSI output is valid
on the falling edge of SCK. Serial data from the 68HC11 is
transmitted in 8-bit bytes with only eight falling clock edges
occurring in the transmit cycle.
03734-034
MC68HC11
AD5383
MISO
MOSI
SCK
PC7
SDO
RESET
SER/PAR
DIN
SCLK
SYNC
SPI/I
2
C
DV
DD
Figure 34. AD5383-to-MC68HC11 Interface
03734-035
µCONTROLLER/
DSP PROCESSOR*
AD5383
ADDRESS
DECODE
UPPER BITS OF
ADDRESS BUS
DATA
BUS
D15
D0
A4
A3
A2
A1
A0
R/W
A4
A3
A2
A1
A0
WR
REG1
REG0
D11
D0
CS
LDAC
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 35. AD5383-to-Parallel Interface