USB4624 datasheet(36/68 Pages) SMSC

36 / 68 page

USB 2.0 HSIC Hi-Speed 4-Port Hub Controller

Datasheet

Revision 1.0 (06-17-13)

SMSC USB4624

DATASHEET

7.1.8

JEDEC-ID Read Example

To perform a JEDEC-ID command, the device writes 0x9F into the first byte of the SPI_CMD_BUF.

The length of the transfer is 4 bytes. The device first drives SPI_CE_N low, then SPI_DO is output

with 8 bits of the command, followed by the 24 bits of dummy bytes (due to the length being set to 4).

When the transfer is complete, SPI_CE_N goes high. After the first byte, the data on SPI_DI is clocked

into the SPI_RSP_BUF. At the end of the command, there are three valid bytes in the SPI_RSP_BUF.

In this example, 0xBF, 0x25, 0x8E.

7.2

SMBus Slave Interface

The USB4624 includes an integrated SMBus slave interface, which can be used to access internal

device run time registers or program the internal OTP memory. SMBus detection is accomplished by

detection of pull-up resistors (10 K

Ω recommended) on both the SMBDATA and SMBCLK signals. To

disable the SMBus, a pull-down resistor of 10 K

Ω must be applied to SMBDATA. The SMBus interface

can be used to configure the device as detailed in Section 6.1, "Configuration Method Selection," on

page 27.

Note: All device configuration must be performed via the SMSC Pro-Touch Programming Tool. For

additional information on the Pro-Touch programming tool, contact your local SMSC sales

representative.

Figure 7.6 SPI JEDEC-ID Read Sequence

SPI_CE_N

SPI_CLK

SPI_DO

SPI_DI

MSB

HIGH IMPEDANCE

11 12 13 14 15 16

12 3 4

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

MSB

USB4624 Datenblatt(PDF) 36 Page - SMSC Corporation