Datasheet

21 SERDESUB-21USB User’s Guide SNLU101 – April 2012
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 (as per default
positions defined in “Configuration Settings for the Serializer/Deserializer Demo
Board” tables).
3) Connect the USB interface cable between P2 (DS90UB903Q board) connector and
J2 connector (DS90UB904Q board).
4) Set hardware configuration for DS90UB903Q Serializer and DS90UB904Q
Deserializer devices
a. Verify 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. DS90UB903Q Serializer (0xB0)
i. Write 0xA0 (Slave Address) to Register 0x07 of Serializer (0xB0)
ii. Write 0xC0 (Deserializer Address) to Register 0x06 of Serializer
(0xB0) (0xC0 is written by default upon power cycling on PDB)
8) Verify that LOCK LED2 on the Deserializer board is lit; This indicates the chipset is
Locked
9) After initialization, the PCLK clock and input data can begin transmission to the
Serializer. The Serializer locks onto PCLK input (if present) otherwise the on-chip
oscillator (25 MHz) is used as the input clock source. Note the user should monitor
the LOCK pin and confirm LOCK = H before performing any I
2
C communication
across the link.