W5500 datasheet(13/66 Pages) WIZNET

13 / 66 page

W5500 Datasheet Version1.0.9

13 / 66

The W5500 supports SPI Mode 0 and Mode 3. Both MOSI and MISO signals use transfer

sequence from Most Significant Bit (MSB) to Least Significant Bit (LSB) when MOSI

signal transmits and MISO signal receives. MOSI & MISO signals always transmit or

receive in sequence from the Most Significant Bit (MSB) to Least Significant Bit (LSB).

Figure 6. SPI Mode 0 & 3

2.1

SPI Operation Mode

W5500 is controlled by SPI Frame (Refer to the Chapter 2.2 SPI Frame) which

communicates with the External Host. W5500 SPI Frame consists 3 phases, Address

Phase, Control Phase and Data Phase.

Address Phase specifies 16 bits Offset Address for W5500 Register or TX/RX Memory.

Control Phase specifies the block to which Offset (set by Address Phase) belongs, and

specifies Read/Write Access Mode and SPI Operation Mode (Variable Length Data /

Fixed Length Data Mode).

And Data Phase specifies random length (N-bytes, 1 ≤ N) Data or 1 byte, 2 bytes and

4 bytes Data.

If SPI Operation Mode is set as Variable Length Data Mode (VDM), SPI Bus Signal SCSn

must be controlled by the External Host with SPI Frame step.

At the Variable Length Data Mode, SCSn Control Start (Assert (High-to-Low)) informs

W5500 of SPI Frame Start (Address Phase), and SCSn Control End (De-assert (Low-to-

High) informs W5500 of SPI Frame End (Data Phase End of random N byte).

SCLK

MISO/MOSI

Sampling

Toggling

Mode 3 : SCLK idle level high

SCLK

MISO/MOSI

Sampling

Toggling

Mode 0 : SCLK idle level low

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