Samsung S3C2440A User Manual

Page 474

Advertising
background image

SPI

S3C2440A RISC MICROPROCESSOR

22-4

SPI TRANSFER FORMAT

The S3C2440A supports 4 different formats to transfer data. Figure 22-2 shows the four waveforms for SPICLK.

*

LSB of previously transmitted character

Cycle

MOSI

1

2

3

4

5

6

7

8

MSB

6

5

4

3

2

1

LSB

6

5

4

3

2

1

LSB

SPICLK

MISO

MSB

CPOL = 1, CPHA = 1 (Format B)

*

MSB of character just received

Cycle

MOSI

1

2

3

4

5

6

7

8

MSB

6

5

4

3

2

1

LSB

6

5

4

3

2

1

LSB

MSB*

SPICLK

MISO

MSB

CPOL = 1, CPHA = 0 (Format A)

Cycle

MOSI

1

2

3

4

5

6

7

8

6

5

4

3

2

1

LSB

6

5

4

3

2

1

LSB*

SPICLK

MISO

*LSB

CPOL = 0, CPHA = 1 (Format B)

*

MSB of character just received

Cycle

MOSI

1

2

3

4

5

6

7

8

MSB

6

5

4

3

2

1

LSB

6

5

4

3

2

1

LSB

MSB*

SPICLK

MISO

MSB

CPOL = 0, CPHA = 0 (Format A)

*

LSB of previously transmitted character

*LSB

MSB

MSB

Figure 22-2 SPI Transfer Format

Advertising