Datasheet STTS22H (STMicroelectronics) - 8

STTS22H Digital interfaces 5 Digital interfaces
The STTS22H communicates over a 2-wire serial interface compatible with the SMBus 3.0 standard and I²C standard.
5.1 SMBus interface 5.1.1 SMBus protocol
The STTS22H communicates over a 2-wire serial interface compatible with the SMBus standard. Temperature data, alarm limits and configuration information are communicated over the bus. A detailed timing diagram is shown below in following figure.
Figure 3. SMBus timing diagram
TLOW THIGH THD; STA TSU:STO SMCLK TR TF THD; STA T T HD:DAT SU:STA T SMDATA SU:DAT P S S P TBUF S - start condition P - stop condition The STTS22H supports standard SMBus 3.0 protocols (see corresponding tables in the following sections). • WRITE byte • READ byte • SEND byte • RECEIVE byte • Alert response address
5.1.2 WRITE byte
The WRITE byte protocol is used to write one byte of data to the registers as shown in the following table. ACK data are sent by the STTS22H while all other data are sent by the host.
Table 6. SMBus WRITE protocol Slave Register Start WR ACK ACK data ACK stop address address
1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 8 bits 1 bit 1 bit
DS12606
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Rev 4 page 8/29
Document Outline 1 Overview 2 Pin description 3 Sensor parameters and electrical specifications 3.1 Sensor accuracy specifications 4 Absolute maximum ratings 5 Digital interfaces 5.1 SMBus interface 5.1.1 SMBus protocol 5.1.2 WRITE byte 5.1.3 READ byte 5.1.4 SEND byte 5.1.5 RECEIVE byte 5.1.6 SMBus timeout 5.1.7 Alert response address 5.2 I²C interface 5.2.1 I²C protocol 5.2.2 I²C read and write sequences 6 Register description 6.1 WHOAMI (01h) - RO 6.2 TEMP_H_LIMIT (02h) - RW 6.3 TEMP_L_LIMIT (03h) - RW 6.4 CTRL (04h) - RW 6.5 STATUS (05h) - RO 6.6 TEMP_L_OUT (06h) - RO 6.7 TEMP_H_OUT (07h) - RO 6.8 SOFTWARE_RESET (0Ch) - RW 7 Interrupt 8 ALERT / INT output 9 Operating modes 9.1 Enable sequence for one-shot mode 9.2 Enable sequence for freerun mode 9.3 Enable sequence for low-ODR mode 10 Package information 10.1 Soldering information 10.2 UDFN-6L package information 10.3 UDFN-6L packing information Revision history