All Sensors

DS-0355 Rev A

Operation Overview

Page 5

Figure 2 - DLH Communication Model

Digital Interface Command Formats

When requesting the start of a measurement, the command format for both I2C and SPI is the same.

When requesting sensor status over I2C, the host simply performs a 1-byte read transfer.

When reading sensor data over I2C, the host simply performs a 7-byte read transfer.

See Table 1 below for Measurement Commands, Sensor Data read and Sensor Status read details.

Table 1 - DLH Sensor Command Set

Start-Single Command

Internal State

Interal Operation

DSP

DSP

New Data Available

EOC

Start-Average2 / 4 / 8 / 16 Commands (Auto Averaging)

Internal State

Interal Operation

DSP

New Data Available

EOC

Idle

Idle

Active

ADC (T, Z, P)…

Idle

Idle

Active

Idle

Idle

Idle

Idle

ADC (Temp, Zero, Pressure)

ADC (Temp, Zero, Pressure)

Data Read

Start-Average2/4/8/16

Active

Command

Start-Single

Data Read

Start-Single

Command

Start-Average2/4/8/16

Active

Idle

Idle

0xAA

0x00

0x00

0xAC

0x00

0x00

0xAD

0x00

0x00

0xAE

0x00

0x00

0xAF

0x00

0x00

I2C

SPI

I2C

SPI

Read of 1 byte from device.

Read of 1 byte from device

Host must send [0xF0] on MOSI

Sensor Returns 1 byte on MISO

Start‐Average8

Start‐Average16

Read Sensor Data

Read of 7 bytes from device

Read of 7 bytes from device

Host must send [0xF0], then 6 bytes of [0x00] on MOSI

Sensor Returns 7 bytes on MISO

Read Sensor Status

Start‐Average4

Measurement Commands (I2C or SPI)

Description

Command ( 3 bytes )

Start‐Single

Start‐Average2