AD7715ANZ-3 Analog Devices Inc, AD7715ANZ-3 Datasheet - Page 26

• Manufacturer Part Number: AD7715ANZ-3
• Description: IC ADC 16BIT SIGMA-DELTA 16DIP
• Manufacturer: Analog Devices Inc

Specifications of AD7715ANZ-3

• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Bits: 16
• Sampling Rate (per Second): 500
• Number Of Converters: 1
• Power Dissipation (max): 9.5mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• Resolution (bits): 16bit
• Input Channel Type: Differential
• Supply Voltage Range - Analogue: 3V To 3.6V
• Supply Voltage Range - Digital: 3V To 5.25V
• Supply Current: 600µA
• No. Of: RoHS Compliant
• Sampling Rate: 19.2kSPS
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD7715-3EBZ - BOARD EVALUATION FOR AD7715
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7715
/* This program has read and write routines for the 68HC11 to interface to the AD7715 and the sample
program sets the various registers and then reads 1000 samples from the part. */
#include <math.h>
#include <io6811.h>
#define NUM_SAMPLES 1000 /* change the number of data samples */
#define MAX_REG_LENGTH 2 /* this says that the max length of a register is 2 bytes */
Writetoreg (int);
Read (int,char);
char *datapointer = store;
char store[NUM_SAMPLES*MAX_REG_LENGTH + 30];
void main()
{
of PORTC is made as an output */
char a;
DDRC = 0x04; /* PC2 is an output the rest of the port bits are inputs */
PORTC | = 0x04;
Writetoreg(0x10); /* set the gain to 1, standby off and set the next operation as write to the setup
register */
Writetoreg(0x68); /* set bipolar mode, buffer off, no filter sync, confirm clock as 2.4576MHz, set
output rate to 60Hz and do a self calibration */
while(PORTC & 0x10); /* wait for /DRDY to go low */
for(a=0;a<NUM_SAMPLES;a++);
}
Writetoreg(int byteword);
{
int q;
SPCR = 0x3f;
SPCR = 0X7f; /* this sets the WiredOR mode(DWOM=1), Master mode(MSTR=1), SCK idles high(CPOL=1), /SS
can be low always (CPHA=1), lowest clock speed(slowest speed which is master clock /32 */
DDRD = 0x18; /* SCK, MOSI outputs */
q = SPSR;
q = SPDR;
which tells the user that the data transfer is complete */
PORTC &= 0xfb; /* /CS is low */
SPDR = byteword;
while(!(SPSR & 0x80));
PORTC |= 0x4;
}
Read(int amount, int reglength)
{
int q;
SPCR = 0x3f;
SPCR = 0x7f;
DDRD = 0x10;
while(PORTC & 0x10);
PORTC & 0xfb ; /* /CS is low */
for(b=0;b<reglength;b++)
PORTC|=4; /* /CS is high */
}
/* the only pin that is programmed here from the 68HC11 is the /CS and this is why the PC2 bit
{
Writetoreg(0x38); /*set the next operation for 16 bit read from the data register */
Read(NUM_SAMPLES,2);
}
{
SPDR = 0;
while(!(SPSR & 0x80));
*datapointer++=SPDR;
}
/* the read of the staus register and of the data register is needed to clear the interrupt
/* clear the interrupt */
/* MOSI output, MISO input, SCK output */
/* /CS high */
/* make the /CS line high */
/* put the byte into data register */
/* wait for /DRDY to go low */
/* wait for /DRDY to go low */
/* read SPDR into store array via datapointer */
Table XVI. C Code for Interfacing AD7715 to 68HC11
/* wait until port ready before reading */
–26–
REV. C