AD5532HS Analog Devices, AD5532HS Datasheet - Page 9

• Manufacturer Part Number: AD5532HS
• Description: 32-Channel 14-Bit bipolar DAC with High Speed 3-Wire Serial Interface
• Manufacturer: Analog Devices

Specifications of AD5532HS

• Resolution (bits): 14bit
• Dac Update Rate: 1.1MSPS
• Dac Settling Time: 10µs
• Max Pos Supply (v): +12V
• Single-supply: No
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

MICROPROCESSOR INTERFACING
AD5532HS-to-ADSP-21xx Interface
The ADSP-21xx family of DSPs are easily interfaced to the
AD5532HS without the need for extra logic.
A data transfer is initiated by writing a word to the Tx register
after the SPORT has been enabled. In a write sequence, data is
clocked out on each rising edge of the DSP’s serial clock and
clocked into the AD5532HS on the falling edge of its SCLK.
The easiest way to provide the 19-bit data-word required by
the AD5532HS, is to transmit two 10-bit data-words from the
ADSP-21xx. Ensure that the data is positioned correctly in the
TX register so that the first 19 bits transmitted contain valid
data. The SPORT control register should be set up as follows:
TFSW
INVTFS = 1, Active Low Frame Signal
DTYPE = 00, Right Justify Data
ISCLK = 1, Internal Serial Clock
TFSR
ITFS
SLEN
Figure 3 shows the connection diagram.
AD5532HS-to-MC68HC11 Interface
The Serial Peripheral Interface (SPI) on the MC68HC11 is
configured for Master Mode (MSTR = 1), 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
68HC11 User Manual. SCK of the 68HC11 drives the SCLK of
the AD5532HS and the MOSI output drives the serial data line
(D
line (PC7). When data is being transmitted to the AD5532HS, the
SYNC line is taken low (PC7). Data appearing on the MOSI
output is valid on the falling edge of SCK. The 68HC11 transfers
only eight bits of data during each serial transfer operation;
therefore, three consecutive write operations are necessary to
transmit 19 bits of data. Data is transmitted MSB first. It is
important to left-justify the data in the SPDR register so that
the first 19 bits transmitted contain valid data. PC7 must be
pulled low to start a transfer. It is taken high and pulled low
again before any further write cycles can take place. See Figure 4.
REV. 0
Figure 3. AD5532HS-to-ADSP-2101/ADSP-2103 Interface
*ADDITIONAL PINS OMITTED FOR CLARITY
*ADDITIONAL PINS OMITTED FOR CLARITY
IN
) of the AD5532HS. The SYNC signal is derived from a port
AD5532HS*
AD5532HS*
Figure 4. AD5532HS-to-MC68HC11 Interface
= 1, Alternate Framing
= 1, Frame Every Word
= 1, Internal Framing Signal
= 1001, 10-Bit Data Word
SCLK
SYNC
SYNC
SCLK
D
D
IN
IN
SCLK
DT
TFS
SCK
MOSI
PC7
ADSP-2103*
ADSP-2101/
MC68HC11*
–9–
AD5532HS-to-PIC16C6x/7x Interface
The PIC16C6x/7x Synchronous Serial Port (SSP) is configured
as an SPI Master with the Clock Polarity bit = 0. This is done
by writing to the Synchronous Serial Port Control Register
(SSPCON). See user PIC16/17 Microcontroller User Manual.
In this example I/O port RA1 is being used to pulse SYNC
and enable the serial port of the AD5532HS. This microcontroller
transfers only eight bits of data during each serial transfer
operation; therefore, three consecutive write operations are
necessary to transmit 19 bits of data. Data is transmitted MSB
first. It is important to left-justify the data in the SPDR register
so that the first 19 bits transmitted contain valid data. RA1
must be pulled low to start a transfer. It is taken high and pulled
low again before any further write cycles can take place. Figure 5
shows the connection diagram.
AD5532HS-to-8051 Interface
The AD5532HS requires a clock synchronized to the serial
data. The 8051 serial interface must therefore be operated in
Mode 0. In this mode serial data exits the 8051 through RxD
and a shift clock is output on TxD. The SYNC signal is derived
from a port line (P1.1). Figure 6 shows how the 8051 is connected
to the AD5532HS. Because the AD5532HS shifts data out on
the rising edge of the shift clock and latches data in on the
falling edge, the shift clock must be inverted. Note also that
the AD5532HS requires its data with the MSB first. Since the
8051 outputs the LSB first, the transmit routine must take this
into account.
*ADDITIONAL PINS OMITTED FOR CLARITY
*ADDITIONAL PINS OMITTED FOR CLARITY
AD5532HS*
AD5532HS*
Figure 5. AD5532HS-to-PIC16C6x/7x Interface
Figure 6. AD5532HS-to-8051 Interface
SYNC
SCLK
SCLK
SYNC
D
D
IN
IN
AD5532HS
TxD
RxD
P1.1
SCK/RC3
SDI/RC4
RA1
PIC16C6x/7x*
8051*