LPS35HW datasheet(26/48 Pages) STMICROELECTRONICS

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Digital interfaces

LPS35HW

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DocID029129 Rev 1

in the case of multiple read/write bytes. Bit duration is the time between two falling edges of

SPC. The first bit (bit 0) starts at the first falling edge of SPC after the falling edge of CS

while the last bit (bit 15, bit 23,...) starts at the last falling edge of SPC just before the rising

edge of CS.bit0: RW bit. When 0, the data DI(7:0) is written into the device. When 1, the

data DO(7:0) from the device is read. In the latter case, the chip will drive SDO at the start

of bit 8.

bit1-7: address AD(6:0). This is the address field of the indexed register.

bit8-15: data DI(7:0) (write mode). This is the data that is written into the device (MSb first).

bit8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first).

In multiple read/write commands further blocks of 8 clock periods are added. When the

IF_ADD_INC bit is 0, the address used to read/write data remains the same for every

block. When the IF_ADD_INC bit is 1, the address used to read/write data is incremented

at every block.

The function and the behavior of SDI and SDO remain unchanged.

6.5

SPI read

Figure 15: SPI read protocol

The SPI read command is performed with 16 clock pulses. The multiple byte read

command is performed by adding blocks of 8 clock pulses to the previous one.

bit0: READ bit. The value is 1.

bit1-7: address AD(6:0). This is the address field of the indexed register.

bit8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first).

bit16-...: data DO(...-8). Further data in multiple byte reads.

LPS35HW 데이터시트(PDF) 26 Page - STMicroelectronics