SPI bus protocol

STA5620

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6

SPI bus protocol

The SPI port is used for data exchange between STA5620 and a GPS base band. The SPI

port is controlled by four pins SPI_CLK, SPI_DI, SPI_DO and SPI_CS/. These pins are

inputs only, except for SPI_DO, the data output. The SPI Bus protocol is based on a 2-phase

transfer made of an address cycle and a data cycle.

The two functions in the bus interface layer are:

Figure 3.

SPI byte write

Figure 4.

SPI byte read

6.1

SPI_CS/

This package pin provides the frame and CS/ connection for the serial interface (SPI). This

pin will always be an input.

6.2

SPI_CLK

This package pin provides the clock connection for the serial interface (SPI). This pin will

always be an input.

6.3

SPI_DI

This package pin provides the data input connection for the serial interface (SPI). This pin

will always be an input.

6.4

SPI_DO

This package pin provides the data output connection for the serial interface (SPI). This pin

will always be an output.

CS/

SCLK

SDI

SDO

A7

A6

A5

A4

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

AC00327

CS/

SCLK

SDI

SDO

A7

A6

A5

A4

A3

A2

A1

A0

D7

D6

D5

D4

D3

D2

D1

D0

AC00326