Datasheet

SNLU100 – April 2012 SERDESUB-16USB User’s Guide 25
Procedure - Display 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.
NOTE: For Display Mode, the default settings for switch S1-M_S on S1 for the
DS90UB901Q Serializer and DS90UB902Q Deserializer boards must be reversed.
DS90UB901Q board: S1 DS90UB902Q board: S1
3) Connect the USB interface cable between P3 (DS90UB901Q board) connector and
J2 connector (DS90UB902Q board).
4) Set hardware configuration for DS90UB901Q Serializer and DS90UB902Q
Deserializer devices
a. Peripheral device (display) address is set to 0xA0
b. Set to Display mode: Serializer MODE (M_S) pin = H and Deserializer
MODE (M_S) pin = L
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) Before initiating any I
2
C commands, the Serializer needs to be programmed with
the target slave device address and Deserializer device address. DES_DEV_ID
Register 0x06h sets the Deserializer device address and SLAVE_DEV_ID register
0x7h sets the remote target slave address. If the I
2
C slave address matches any of
registers values, the I
2
C slave will hold the transaction allowing read or write to
target device. Note: In Display mode operation, registers 0x08h~0x17h on
Deserializer must be reset to 0x00.
7) Execute I
2
C instructions to write the following registers
a. DS90UB901Q Serializer (0xB0)
b. Set target slave device address on the Serializer
i. Write 0xA0 to Register 0x07 of Serializer (0xB0)