ADC Control Registers
733
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Analog To Digital Converter (ADC) Module
Table 19-12. ADC Group 2 Operating Mode Control Register (ADG2MODECR)
Field Descriptions
Field
Value
Description
Reserved
0
Reads return zeros, writes have no effect.
No Reset on ChnSel
No Group2 Results Memory Reset on New Channel Select. This bit determines whether the group2
results’ RAM is reset whenever a non-zero value is written to the group2 channel select register.
Any operation mode read/write:
0
Group2 results RAM is reset when a non-zero value is written to group2 channel select register, even if
group2 conversions are completed.
1
Group2 results RAM is not reset when a non-zero value is written to group2 channel select register,
and group2 conversions are completed.
If the group2 conversions are ongoing (active or frozen), then writing a nonzero value to the group2
channel select register will always reset the group2 results RAM.
Reserved
0
Reads return zeros, writes have no effect.
G2_DATA_FMT
Group2 Read Data Format. This field is only applicable when the ADC module is configured to be a
12-bit ADC module. This field determines the format in which the conversion results are read out of the
group1 results RAM when using the FIFO interface, that is, when reading from the ADG2BUFFER or
ADG2EMUBUFFER locations.
Any operation mode read/write:
0
Conversion results are read out in full 12-bit format. This is the default mode.
1h
Conversion results are read out in 10-bit format. Bits 11-2 of the 12-bit conversion result are returned
as the 10-bit conversion result.
2h
Conversion results are read out in 8-bit format. Bits 11-4 of the 12-bit conversion result are returned as
the 8-bit conversion result.
3h
Reserved. The full 12-bit conversion result is returned if programmed.
Reserved
0
Reads return zeros, writes have no effect.
G2_CHID
Enable Channel Id for the Group2 conversion results to be read. This bit only affects the “read from
FIFO” mode. The ADC always stores the channel id in the results RAM. Any 16-bit read performed in
the “read from RAM” mode will return the 5-bit channel id along with the 10-bit conversion result.
Any operation mode read/write:
0
Bits 14-10, the channel id field, of the data read from the Group2 results’ FIFO is read as 00000b.
1
Bits 14-10, the channel id field, of the data read from the Group2 results’ FIFO contains the number of
the ADC analog input to which the conversion result belongs.
OVR_G2_RAM_IGN
This bit allows the ADC module to overwrite the contents of the Group2 results memory under an
overrun condition.
Any operation mode read/write:
0
The ADC cannot overwrite the contents of the Group2 results memory. When an overrun of this
memory occurs, the software needs to read out all the contents of this memory before the ADC is able
to write a new conversion result for the Group2.
1
When an overrun of the Group2 results memory occurs, the ADC proceeds to overwrite the contents
with any new conversion results for the Group2, starting with the first location in this memory.
G2_HW_TRIG
Group2 Hardware Triggered. This bit allows the Group2 to be hardware triggered. The Group2 is
software triggered by default. For more details on how to trigger a conversion group, please refer to
Any operation mode read/write:
0
The Group2 is software-triggered. A Group2 conversion starts whenever the Group2 channel select
register (ADG2SEL) is written with a non-zero value.
1
The Group2 is hardware-triggered. A Group2 conversion starts whenever the Group2 channel select
register has a non-zero value, and the specified hardware trigger occurs. The hardware trigger for the
Group2 is specified in the Group2 Trigger Source register (ADG2SRC).
G2_8BIT
Group2 8-bit result mode. This bit is only applicable when the ADC module is configured to be a 10-bit
ADC module. This bit allows the Group2 conversion results to be read out in an 8-bit format. This bit
only applies to the “read from FIFO” mode. The lower 2 bits of the 10-bit conversion result are
discarded and the upper 8 bits are shifted right two places to form the 8-bit conversion result.
Any operation mode read/write:
0
The Group2 conversion result is read out as a 10-bit value in the “read from Group2 FIFO” mode.
1
The Group2 conversion result is read out as an 8-bit value in the “read from Group2 FIFO” mode.
