MSP430 datasheet(31/88 Pages) TI

31 / 88 page

To use the ADC, first enable the ADC buffer by setting ADC_CFG.BUF_PD = 0. Then wait at least 210 μs

before setting the trigger using the TRIGGER.ADC bit. An internal delay is forced if the trigger signal is sent

before the timer has expired. Make sure the ADC is not converting before setting the ADC_CFG.BUF_PD = 1. If

ADC_CFG.BUF_PD is set to 1 while the ADC is still converting, the internal timer delays this command. When

the timer expires, the enable signal for the ADC is cleared, and the current conversion finishes before powering

down the ADC and the ADC Buffer.

A trigger signal must occur for the ADC to exit the idle state. The ADC trigger is generated through the

TRIGGER.ADC bit. The ADC data registers have the latest available data. Accessing the data registers does not

interfere with the conversion process, and thus provides continuous ADC operation.

In direct-mode conversion, the selected ADC input channels are converted on demand by issuing an ADC trigger

signal. After the last enabled channel is converted, the ADC enters the idle state and waits for a new trigger.

Read the results of the ADC conversion through the register map. Direct-mode conversion is typically used to

gather the ADC data of any of the data channels. In direct-mode, use the ADC_BUSY bit to determine when a

direct-mode conversion is complete and the ADC has returned to the idle state. Direct mode is set by writing

ADC_CFG.DIRECT_MODE = 1.

In auto-mode conversion, the selected ADC input channels are converted continuously. The conversion cycle

is initiated by issuing an ADC trigger. Upon completion of the first conversion sequence, another sequence is

automatically started. Conversion of the selected channels occurs repeatedly until the auto-mode conversion is

stopped by clearing the ADC trigger signal. Auto-mode conversion is not typically used to gather the ADC data.

Instead, auto-mode conversions are used in combination with upper and lower ADC data thresholds to detect

when the data has exceeded the programmable out-of-range alarm thresholds. Auto mode is set by writing

ADC_CFG.DIRECT_MODE = 0.

Regardless of the selected conversion method, update the ADC configuration register only while the ADC is in

the idle state. Do not change the ADC configuration bits while the ADC is converting channels. Before changing

configuration bits, disable the ADC and verify that GEN_STATUS.ADC_BUSY = 0.

www.ti.com

AFE78101, AFE88101

SLASF21 – DECEMBER 2022

Submit Document Feedback

Product Folder Links: AFE78101 AFE88101

MSP430 датащи(PDF) 31 Page - Texas Instruments