HS300x Datasheet

© 2021 Renesas Electronics Corporation

13

April 20, 2021

6.7 Status Bits

The status bits are used to indicate the current state of the fetched data. The two MSBs of the humidity data byte are the status bits (see the

following table).

Table 7.

Status Bits

Status Bits

Definition

Valid Data: Data that has not been fetched since the last measurement cycle

Stale Data: Data that has already been fetched since the last measurement cycle

Note: If a data fetch is performed before or during the first measurement after power-on reset, then the stale status will be

returned, but this data is actually invalid since the first measurement has not been completed.

6.8 Accessing the Non-volatile Memory

The HS300x series non-volatile memory stores its measurement resolution setting and its ID number. To change the sensor resolution or read

the ID number, the master must place the HS300x into programming mode while the chip is powering up. The figure below shows the sequence

of commands needed to enter the programming mode, which must be sent within 10ms after applying power to the sensor. The master must

Figure 18. Sequence of Commands to Enter Programming Mode

This command takes 120µs to process, after which the master has access to the non-volatile memory registers listed in the following table. All

of these registers are 16 bits wide.

command: 0x80|0x00|0x00.

Table 8.

Non-volatile Memory Registers

Address

Register Description

0x06

Humidity Sensor Resolution – Read Register (bits [11:10])

0x46

Humidity Sensor Resolution – Write Register (bits [11:10])

0x11

Temperature Sensor Resolution – Read Register (bits [11:10])

0x51

Temperature Sensor Resolution – Write Register (bits [11:10])

0x1E

Read Sensor ID – Upper 2 bytes

0x1F

Read Sensor ID – Lower 2 bytes