ADS1242 AND ADS1243 CONTROL COMMAND DEFINITIONS
The commands listed in Table IV control the operations of
the ADS1242 and ADS1243. Some of the commands are
stand-alone commands (for example, RESET) while others
require additional bytes (for example, WREG requires the
count and data bytes).
Operands:
n = count (0 to 127)
r = register (0 to 15)
x = don’t care
COMMANDS
DESCRIPTION
OP CODE
2nd COMMAND BYTE
RDATA
RDATAC
STOPC
RREG
WREG
SELFCAL
SELFOCAL
SELFGCAL
SYSOCAL
SYSGCAL
WAKEUP
DSYNC
Read Data
Read Data Continuously
Stop Read Data Continuously
Read from REG “rrrr”
Write to REG “rrrr”
Offset and Gain Self Cal
Self Offset Cal
Self Gain Cal
Sys Offset Cal
Sys GainCal
Wakup from SLEEP Mode
Sync DRDY
0000 0001 (01H)
0000 0011 (03H)
0000 1111 (0FH)
0001 r r r r (1xH)
0101 r r r r (5xH)
1111 0000 (F0H)
1111 0001 (F1H)
1111 0010 (F2H)
1111 0011 (F3H)
1111 0100 (F4H)
1111 1011 (FBH)
1111 1100 (FCH)
1111 1101 (FDH)
1111 1110 (FEH)
—
—
—
xxxx_nnnn (# of regs-1)
xxxx_nnnn (# of regs-1)
—
—
—
—
—
—
—
—
—
SLEEP
RESET
Put in SLEEP Mode
Reset to Power-Up Values
NOTE: The received data format is always MSB first; the data out format is set by the BIT ORDER bit in the ACR register.
TABLE IV. Command Summary.
RDATA–Read Data
RDATAC–Read Data Continuous
Description:Readthemostrecentconversionresultfromthe
Data Output Register (DOR). This is a 24-bit value.
Description: Read Data Continuous mode enables the con-
tinuous output of new data on each DRDY. This command
eliminates the need to send the Read Data Command on each
DRDY. This mode may be terminated by either the STOPC
command or the RESET command. Wait at least 10 fOSC after
DRDY falls before reading.
Operands: None
Bytes:
1
Encoding: 0000 0001
Data Transfer Sequence:
Operands: None
Bytes:
1
0000 0001
• • •(1)
xxxx xxxx
MSB
xxxx xxxx
Mid-Byte
xxxx xxxx
LSB
DIN
Encoding: 0000 0011
Data Transfer Sequence:
Command terminated when “uuuu uuuu” equals STOPC or
DOUT
RESET.
NOTE: (1) For wait time, refer to timing specification.
DRDY
DIN
0000 0011
• • •(1)
uuuu uuuu
MSB
uuuu uuuu
Mid-Byte
uuuu uuuu
LSB
• • •
DOUT
DRDY
DOUT
• • •
MSB
Mid-Byte
LSB
NOTE: (1) For wait time, refer to timing specification.
ADS1242, 1243
18
SBAS235B
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