LM3S6753 Datasheet, PDF (288/625 Pages) Texas Instruments – Stellaris LM3S6753 Microcontroller

Analog-to-Digital Converter (ADC)
12.3.2
Sample Sequencer Configuration
Configuration of the sample sequencers is slightly more complex than the module initialization since
each sample sequence is completely programmable.
The configuration for each sample sequencer should be as follows:
1. Ensure that the sample sequencer is disabled by writing a 0 to the corresponding ASENn bit in
the ADCACTSS register. Programming of the sample sequencers is allowed without having
them enabled. Disabling the sequencer during programming prevents erroneous execution if a
trigger event were to occur during the configuration process.
2. Configure the trigger event for the sample sequencer in the ADCEMUX register.
3. For each sample in the sample sequence, configure the corresponding input source in the
ADCSSMUXn register.
4. For each sample in the sample sequence, configure the sample control bits in the corresponding
nibble in the ADCSSCTLn register. When programming the last nibble, ensure that the END bit
is set. Failure to set the END bit causes unpredictable behavior.
5. If interrupts are to be used, write a 1 to the corresponding MASK bit in the ADCIM register.
6. Enable the sample sequencer logic by writing a 1 to the corresponding ASENn bit in the
ADCACTSS register.
12.4
Register Map
Table 12-3 on page 288 lists the ADC registers. The offset listed is a hexadecimal increment to the
register’s address, relative to the ADC base address of 0x4003.8000.
Table 12-3. ADC Register Map
Offset Name
Type
0x000 ADCACTSS
0x004 ADCRIS
0x008 ADCIM
0x00C ADCISC
0x010 ADCOSTAT
0x014 ADCEMUX
0x018 ADCUSTAT
0x020 ADCSSPRI
0x028 ADCPSSI
0x030 ADCSAC
0x040 ADCSSMUX0
0x044 ADCSSCTL0
0x048 ADCSSFIFO0
R/W
RO
R/W
R/W1C
R/W1C
R/W
R/W1C
R/W
WO
R/W
R/W
R/W
RO
Reset
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.0000
0x0000.3210
-
0x0000.0000
0x0000.0000
0x0000.0000
-
Description
ADC Active Sample Sequencer
ADC Raw Interrupt Status
ADC Interrupt Mask
ADC Interrupt Status and Clear
ADC Overflow Status
ADC Event Multiplexer Select
ADC Underflow Status
ADC Sample Sequencer Priority
ADC Processor Sample Sequence Initiate
ADC Sample Averaging Control
ADC Sample Sequence Input Multiplexer Select 0
ADC Sample Sequence Control 0
ADC Sample Sequence Result FIFO 0
See
page
290
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288
April 05, 2010
Texas Instruments-Production Data