7.3.2.2 ADC Sequencing

The AMC7836 ADC conversion sequence is shown in Figure 52. The ADC supports direct mode and auto mode conversion. The conversion method is selected in the ADC configuration register (address 0x10). The default conversion method is direct mode.

In both methods, the single channel or sequence of channels to be converted by the ADC must be first configured in the ADC MUX configuration registers (address 0x13 through 0x15). The input channels to the ADC include 16 external bipolar inputs, five external unipolar inputs, and the internal temperature sensor.

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 IDLE state and waits for a new trigger.

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 issuing a second trigger signal.

Figure 52. ADC Conversion Sequence

Regardless of the selected conversion method, the following ADC registers should only be updated while the ADC is in IDLE state:

• ADC configuration register (address 0x10)
• False alarm configuration register (address 0x11)
• ADC MUX configuration registers (address 0x13 through 0x15)
• Threshold registers (0x80 through 0x97)
• Hysteresis register (0xA0 through 0xA5)