Datasheet

DIN

DOUT

VBIAS

00100001 00000001

1st

Command

Byte

2nd

Command

Byte

MUX1

DataByte DataByte

DIN

01000010 00000001 MUX2 SYS0

1st

Command

2nd

Command

Data

Byte

Data

Byte

ADS1246

ADS1247

ADS1248

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SBAS426G –AUGUST 2008–REVISED OCTOBER 2011

USER REGISTER READ AND WRITE COMMANDS

RREG—Read from registers.

This command outputs the data from up to 16 registers, starting with the register address specified as part of

the instruction. The number of registers read is one plus the second byte. If the count exceeds the remaining

registers, the addresses wrap back to the beginning.

First Command Byte: 0010 rrrr, where rrrr is the address of the first register to read.

Second Command Byte: 0000 nnnn, where nnnn is the number of bytes to read –1.

It is not possible to use the full-duplex nature of the SPI interface when reading out the register data. For

example, a SYNC command cannot be issued when reading out the VBIAS and MUX1 data, as shown in

Figure 80. Any command sent during the readout of the register data is ignored. Thus, it is advisable to send

NOP through the DIN when reading out the register data.

Figure 80. Read from Register

WREG—Write to registers.

This command writes to the registers, starting with the register specified as part of the instruction. The

number of registers that are written is one plus the value of the second byte.

First Command Byte: 0100 rrrr, where rrrr is the address of the first register to be written.

Second Command Byte: 0000 nnnn, where nnnn is the number of bytes to be written – 1.

Data Byte(s): data to be written to the registers.

Figure 81. Write to Register

Product Folder Link(s): ADS1246 ADS1247 ADS1248