Software Details
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14
SBAU293 – March 2018
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Copyright © 2018, Texas Instruments Incorporated
ADS1261 and ADS1235 Evaluation Module
ADVANCE INFORMATION
(1)
Returns device to previous state after completion.
(2)
Resetting will wake the device from software-power down mode.
(3)
Setting the /PDWN pin high exits hardware power-down mode; however, the previous software power-down mode will remain
unchanged.
Table 7. ADS1261 and ADS1235 EVM Software Commands 1
Command
Command
Arguments
Description
Wakes
Device?
ID
Returns EVM ID string: "<DEVICE> <DATE> <TIME>", where "<DEVICE>" is either "ADS1261" or
"ADS1235", and "<DATE> <TIME>" indicates when the EVM firmware was complied.
N
COMMANDLIST
Returns a list of all commands supported by the EVM firmware.
N
COLLECT
<# Samples>
Collects a number of ADC samples equal to "<# Samples>", where "<# Samples>" is an unsigned
integer. During this operation, all other commands will be ignored and the BUSY LED will blink until all
samples have been collected.
Y
(1)
REGMAP
This command is used by the GUI to read the values of all registers.
Y
(1)
NOP
Issues the NOP device command to the ADC (via SPI).
N
RESET
Issues the RESET device command to the ADC (via SPI).
N
(2)
START
Sets the START pin low and issues the START device command to the ADC (via SPI).
N
STOP
Sets the START pin low and issues the STOP device command to the ADC (via SPI).
N
RDATA
Starts a single conversion, waits for /DRDY to go low, and prints the conversion result to the console.
N
SYOCAL
Issues the system-offset calibration device command to the ADC (via SPI).
N
SYGCAL
Issues the system-gain calibration device command to the ADC (via SPI).
N
SFOCAL
Issues the self-offset calibration device command to the ADC (via SPI).
N
RREG
<ADDRESS>
Issues a read register device command to the ADC (via SPI), where "<ADDRESS>" is the starting
register address in hexadecimal (without the "0x" prefix or "h" postfix).
N
READSINGLE
<ADDRESS>
This command is used by the GUI. It provides the same function as RREG, but wakes the device from
power down and returns to previous power-down mode after completion.
Y
(1)
HOLDCLOCK
<"0" or "1">
This command disables the Tiva GPIO output connected to "EXT CLK" to allow for external clocks to be
applied to J6. Refer to
Section 3.2.2
.
N
WREG
<ADDRESS>
<DATA>
Issues a write register device command to the ADC (via SPI), where "<ADDRESS>" is the starting
register address in hex, and "<DATA>" is the value to write to the register in hex (without the "0x" prefix
or "h" postfix).
N
WRITESINGLE
<ADDRESS>
<DATA>
This command is used by the GUI. It provides the same function as WREG, but wakes the device from
power down and returns to previous power-down mode after completion.
Y
(1)
LOCK
Sends the lock register device command to the ADC (via SPI). While in this mode, all write register
commands will be ignored until the device is unlocked.
N
UNLOCK
Sends the unlock register device command to the ADC (via SPI). This command unlocks the device
register to allow write commands to take effect.
N
HOLDPWDN
<"0" or "1">
This command controls the state of the /PWDN GPIO pin. An argument of "1" sets the /PWDN pin high,
while a "0" argument sets the /PWDN pin low.
·
(3)
HOLDSTART
<"0" or "1">
This command controls the state of the START GPIO pin. An argument of "1" sets the START pin high,
while a "0" argument sets the START pin low.
N
HWRESET
This command toggles the /RESET GPIO pin.
N
(2)
CLEAR
Clears the software fault flag, writes "0x00" to the STATS register (to clear the CRC_ERR and RESET
bits), and turns off the FAULT LED. NOTE: Pressing S3 will perform the same action as the CLEAR
command.
N
STATUS
Reads the STATUS register (to check for any new fault conditions) and prints (to the console) a
description of each fault type that has occurred since last clearing the software fault flag (with S3 or the
CLEAR command).
N
CRC
<LENGTH>
<DATA1>
<DATA2>
<DATA3>
<DATA4>
Computes the CRC-n of the data bytes given in "<DATA1>" through "<DATA4>", where "<LENGTH>" is
the number of bytes to be used in the CRC-n calculation. If the number of data bytes provided is greater
than "<LENGTH>", the extra data bytes will be ignored.
N
DONTCARE
<VALUE>
Sets the "Don't care" byte value that is used for all SPI commands that include a "Don't care" byte.
Changing the value of this byte only has the effect of modifying the resulting CRC byte that is used with
CRC-mode.
N
SPISEND
<LENGTH>
<BYTE1>
<BYTE2> ...
Sends a user-specified SPI command sequence to the ADC. /CS will remain low until all bytes have
been sent. After issuing this command the firmware will read the STATUS register to check for an CRC
errors. This command allows for testing of the CRC command validation of the ADC, for example, since
it allows the user to provide invalid CRC bytes with the various SPI commands.
N
