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AS8650B

Datasheet - Application In form atio n

8.1.2 SPI Read Operation

The SPI read operation also begins with clock polarity selection at negative edge of CS, given in Table 20. Once the clock polarity is selected the

SPI read command is given by providing ‘1’ in R/W bit of the header field in first sampling edge at SDI pin. The 5 bits address of register to be

read is provided at SDI pin in next five consecutive sampling edges of SCLK. The first 2 bits in header fields are reserved and set to ‘0’. The read

data is followed by last bit of header field on SDO pin. With each sampling edge a bit can be read on SDO pin starting from MSB to LSB. During

complete SPI read operation the CS has to be ‘low’. The SPI read operation ends with positive edge of CS. The wave form for SPI read operation

with single data byte is shown in Figure 18 and Figure 19.

Figure 18. SPI Read Operation with Negative Clock Polarity and 1 Byte of Data Field

Figure 19. SPI Read Operation with Positive Clock Polarity and 1 Byte of Data Field

D7

D6

D5

D4

D3

D2

D1

D0

R1

R0

A4

A3

A2

A1

A0

SCLK

SDI

CS

SDO

Sampling Edge

High Impedance Sate

SCLK

SDI

CS

SDO

R1

R0

A4

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

Sampling Edge

High Impedance Sate