EVAL-AD5415EBZ Analog Devices Inc, EVAL-AD5415EBZ Datasheet - Page 23

• Manufacturer Part Number: EVAL-AD5415EBZ
• Description: BOARD EVALUATION FOR AD5415
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD5415EBZ

• Number Of Dac's: 2
• Number Of Bits: 12
• Outputs And Type: 2, Differential
• Sampling Rate (per Second): 2.47M
• Data Interface: Serial
• Settling Time: 120ns
• Dac Type: Current
• Voltage Supply Source: Single
• Operating Temperature: -40°C ~ 125°C
• Utilized Ic / Part: AD5415
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

80C51/80L51-to-AD5415 Interface
A serial interface between the DAC and the 80C51 is shown in
Figure 46. TxD of the 80C51 drives SCLK of the DAC serial
interface, and RxD drives the serial data line, SDIN. P1.1 is a
bit-programmable pin on the serial port and is used to drive
SYNC . When data is to be transmitted to the switch, P1.1 is
taken low. The 80C51/80L51 only transmits data in 8-bit bytes;
therefore, only eight falling clock edges occur in the transmit
cycle. To load data correctly to the DAC, P1.1 is left low after
the first eight bits are transmitted, and a second write cycle is
initiated to transmit the second byte of data. Data on RxD is
clocked out of the microcontroller on the rising edge of TxD
and is valid on the falling edge of TxD. As a result, no glue logic
is required between the DAC and microcontroller interface.
P1.1 is taken high following the completion of this cycle. The
80C51 provides the LSB of its SBUF register as the first bit in
the data stream. The DAC input register requires its data with
the MSB as the first bit received. The transmit routine should
take this into account.
MC68HC11-to-AD5415 Interface
Figure 47 is an example of a serial interface between the DAC
and the MC68HC11 microcontroller. 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 the 68HC11 User Manual . SCK
of the 68HC11 drives the SCLK of the DAC interface; the MOSI
output drives the serial data line (SDIN) of the DAC.
The SYNC signal is derived from a port line (PC7). When data
is being transmitted to the AD5415, 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. Data is transmitted MSB first. To load data
to the DAC, leave PC7 low after the first eight bits are
transferred and perform a second serial write operation to the
DAC. PC7 is taken high at the end of this procedure.
1
ADDITIONAL PINS OMITTED FOR CLARITY.
8051
1
Figure 46. 80C51/80L51-to-AD5415 Interface
P1.1
RxD
TxD
SCLK
SDIN
SYNC
AD5415
1
Rev. B | Page 23 of 32
If the user wants to verify the data previously written to the
input shift register, the SDO line can be connected to MISO of
the MC68HC11, and, with SYNC low, the shift register clocks
data out on the rising edges of SCLK.
MICROWIRE-to-AD5415 Interface
Figure 48 shows an interface between the DAC and any
MICROWIRE-compatible device. Serial data is shifted out on
the falling edge of the serial clock, SK, and is clocked into the
DAC input shift register on the rising edge of SK, which
corresponds to the falling edge of the DAC’s SCLK.
PIC16C6x/7x-to-AD5415 Interface
The PIC16C6x/7x synchronous serial port (SSP) is configured
as an SPI master with the clock polarity bit (CKP) = 0. This is
done by writing to the synchronous serial port control register
(SSPCON); see the PIC16/17 Microcontroller User Manual . In
this example, I/O port RA1 is used to provide a SYNC signal
and enable the serial port of the DAC. This microcontroller
transfers only eight bits of data during each serial transfer
operation; therefore, two consecutive write operations are
required.
1
1
1
ADDITIONAL PINS OMITTED FOR CLARITY.
MICROWIRE
ADDITIONAL PINS OMITTED FOR CLARITY.
PIC16C6x/7x
ADDITIONAL PINS OMITTED FOR CLARITY.
MC68HC11
Figure 49
1
SCK/RC3
SDI/RC4
1
1
Figure 49. PIC16C6x/7x-to-AD5415 Interface
Figure 48. MICROWIRE-to-AD5415 Interface
MOSI
Figure 47. MC68HC11-to-AD5415 Interface
SCK
RA1
PC7
SK
SO
CS
shows the connection diagram.
SYNC
SCLK
SDIN
SCLK
SDIN
SYNC
SCLK
SDIN
SYNC
AD5415
AD5415
AD5415
AD5415
1
1
1