VNC2-32Q1B 参数 Datasheet PDF下载

Document No.: FT_000138

VINCULUM-II EMBEDDED DUAL USB HOST CONTROLLER IC Datasheet

Version -

1.2

Clearance No.: FTDI#

143

6.3.5 Unmanaged Mode

The VNC2 SPI Slave also supports an unmanaged SPI mode. This is a simple data exchange between

Master and Slave. It operates in the standard 4 pin mode (SS#, CLK, MOSI and MISO) with all transfers

controlled by the SPI Master.

When the CPU wants to send data out of the SPI Slave it writes this into the spi_slave_data_tx register.

This will then be moved into the transfer shift register to wait for the SPI Master to request it. The SPI

Master will at some point assert SS# and start clocking data on MOSI with SCK. As this is shifted into the

transfer shift register, the SPI Slave will also be shifting data in the opposite direction on MISO. At the

end of the transfer the SPI Slave copies the received data from the shift register to spi_slave_data_rx as

seen in

SPI Master

SPI Slave

SPI

Clk Div

ss#

clk

0

1

2

3

4

5

6

7

mosi

0

1

2

3

4

5

6

7

Shift Register

Rx Shift Register

0

1

2

3

4

5

6

7

miso

0

1

2

3

4

5

6

7

Shift Register

Tx Shift Register

Figure 6-12 Unmanaged Mode Transfer Diagram

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