ZOPT2202 Datasheet

© 2016 Integrated Device Technology, Inc

17

September 21, 2016

3.5

Conversion Control State Machine

3.5.1 Start Up after Power-On or Software Reset

The main state machine is set to “Start State” during power-on or software reset. As soon as the reset is released, the internal oscillator is

started and the programmed I²C address and the trim values are read from the internal NVM trimming data block. The ZOPT2202 enters

Standby Mode as soon as the Idle State is reached as shown in Figure 3.3.

NOTE: If the I²C address has not yet been read, the device will respond with NACK to any I²C command and ignore any request to avoid

responding to an incorrect I²C address.

If any of the UV operation modes become activated through an I²C command (i.e., the LS_EN bit is set to 1 and the UV mode is selected with

the respective bits in the MAIN_CTRL register), the internal support blocks are immediately powered on. Once the voltages and currents are

settled (typical after 500µs), the state machine checks for trigger events from a measurement scheduler to start conversions according to the

selected measurement repeat rates (see section 3.10.2).

When the user resets the LS_EN bit to 0, a running conversion will be completed and the relevant ADCs and support blocks will move to

Standby Mode thereafter.

Figure 3.3 Main State Machine

Note: See Table 3.4 for a list of the light sensor channels that are active for the configured LS mode.

POR

Standby

LS_EN

!LS_EN

Start oscillator

Start oscillator

Stop oscillator

Run

Read out

NVM fuses

Run

LS

conversion

Wait for repeat

LS_MEAS_RATE

LS_EN

LS inactive

!LS_EN