Set the OPMODE_SEL register to 100b or 101b for manual mode with AUTO sequence. The host must set the SEQ_START bit in the START_SEQUENCE register and provide the device address and read bit to start the conversions. To continue with conversions and reading data, the host must provide continuous SCL (Figure 7-13). In this mode, the SEQ_ABORT bit in the ABORT_SEQUENCE register must be set to abort the operation. Then the device operation mode can be changed to another operation mode. In this mode, a register read aborts the AUTO sequence.

In manual mode, the device always uses the high-speed oscillator and the nCLK parameter has no effect. The maximum scan rate is given by Equation 7:

Equation 7.

• f_s = Maximum sampling speed in kSPS
• T_SCL= Time period of SCL clock (in µs)
• if T_SCL-LOW (low period of SCL) < 1.8.µs, k = (1.8 – T_SCL-LOW) and the device stretches clock in manual mode; not applicable for standard I²C mode (100 kHz)
• if T_SCL-LOW (low period of SCL) ≥ 1.8.µs, k = 0, and the device does not stretch clock in manual mode

A. For setting the operation mode to manual mode, see Figure 7-11.

B. Select manual mode with AUTO sequence in the OPMODE_SEL register. Select channels in the AUTO_SEQ_CHEN register.

C. Set the SEQ_START bit in the START_SEQUENCE register.

D. See Figure 7-13.

E. Set the SEQ_ABORT bit in the ABORT_SEQUENCE register.

F. Select another operation mode in the OPMODE_SEL register.

G. For reading and writing registers, see the Section 7.5 section.

Figure 7-12 Device Operation in Manual Mode

Data can be read from the device by providing a device address and read bit followed by continuous SCL, as shown in Figure 7-13.

A. See Equation 7 for sampling speed in manual mode.

B. If the device scans both channels in AUTO sequence, the first data (for sample A) is from channel 0 and the second data (for sample A +1) is from channel 1.

Figure 7-13 Starting Conversion and Reading Data in Manual Mode