Datasheet

SNLU100 – April 2012 SERDESUB-16USB User’s Guide 21
Procedure - Camera Mode:
1) Connect the 1.8V and 3.3V power with +1.8V and +3.3V supplies accordingly. Keep
the power off.
2) Verify that all the jumper positions and switches are correctly set (as per default
positions defined in “Configuration Settings for the Serializer/Deserializer Demo
Board” tables).
3) Connect the USB interface cable between P3 (DS90UB901Q board) connector and
J2 connector (DS90UB902Q board). Note that hot-plugging assertion of cable
between Serializer and Deserializer is not supported.
4) Set hardware configuration for DS90UB901Q Serializer and DS90UB902Q
Deserializer devices
a. Verify peripheral device (camera) address is set to 0xA0
b. Set to Camera mode: Serializer MODE (M_S) pin = L and Deserializer
MODE (M_S) pin = H
c. Set Serializer and Deserializer I
2
C slave address on ID[x] (CAD) pin:
i. Serializer Rid=0ohm; Serializer I
2
C slave address is 0xB0
ii. Deserializer Rid=0ohm; Deserializer I
2
C slave address is 0xC0
5) Turn on the +1.8V and +3.3V power supplies
6) The DS90UB902Q Deserializer I
2
C slave is enabled to receive data directly from
the I
2
C Master Controller. I
2
C transfers are processed in a one byte basis. After
receiving one byte, the Deserializer slave will need to acknowledge (ACK) the
transfer to receive the next following byte. The Deserializer slave holds SCL low
(clock stretch) for the required period until an ACK (or NACK) is established and
then releases it. The Deserializer I
2
C slave acknowledges all the transfers
addressed to Deserializer, Serializer, or remote device.
7) Before initiating any I
2
C commands, the Deserializer needs to be programmed with
the target slave device addresses and Serializer device address. SER_DEV_ID
Register 0x07h sets the Serializer device address and SLAVE_x_MATCH/
SLAVE_x_INDEX registers 0x08h~0x17h set the remote target slave addresses. In
slave mode the address register is compared with the address byte sent by the I
2
C
master. If the addresses are equal to any of registers values, the I
2
C slave will
acknowledge and hold the bus to propagate the transaction to the target device
otherwise it returns no acknowledge.
8) Execute I
2
C instructions to write the following registers
a. Assign ID Match values for camera address on Deserializer
i. Write 0xA0 to Register 0x08 of Deserializer (0xC0)
ii. Write 0xA0 to Register 0x10 of Deserializer (0xC0)