Device driver for FPDLINK III DS90UH927Q-Q1 and DS90UH928Q-Q1

Hi Ning,

Not sure I follow your question for Linux driver. The DS90UH927/928 is a discrete serializer/deserializer and does not require any drivers to operate. May be you referring to the ALP GUI/software ( www.ti.com/tool/alp ) used to control the device (?) If so, currently only Windows XP is supported.

Dac Tran

SVA APPS

Hi Dac,

When the touch is connected to the deserializer, is I2C on UH928 a master? Can we translate the interrupt through the connection cable to the MCU which is connected to UH927? Do we need SW to do some mapping or control for this application? Do you have an implementation example?

Thanks

Ning

Hi Ning,

The UH928 behaves as an I2C master to the connected touchscreen controller (i2c slave). The UH927/928 chipset will bridge the I2C transactions between MCU and touch slave. You can use the decided GPIO0 pins on the UH927/928 to pass the interrupt signal. Program the following registers:

927: reg0x1D=0x03 – GPIO0 enabled and configured as output

928: reg0x0D=0x05 – GPIO0 enabled and configured as input

Dac Tran

SVA APPS

Hi Dac,

Is there limitation to the LCD resolution for supporting 720p video format under 83MHz?

Ex. LCD resolution 1366x768 (24bpp) with clock rate 79.4MHz. Will it be supported?

Thanks,

Ning

Hi Ning,

Sorry can you clarify your question again?

Standard 1280x720p60 typically operates at 74.25MHz. As long as you operate within the frequency range specified of the LCD panel, then it will work.

Dac Tran

SVA APPS

Hi Dac,

We are tring to verify a LCD that is not in a standard 1280x720 resolution but with resolution 1366x768. It operates at 79.4MHz (from datasheet). Do you mean if we setup the clock rate correctly (79.4MHz) it will be supported by the UH927/UH928?

Thanks,

Ning

Hi Ning,

Hi Dac,

Is it ok to hookup the remote touch interrupt with INTB pin and configure 927 register HDCP ICR to 0x21 for it?

Thanks,

Ning

Hi Ning,

The remotetouch interrupt signal can be connected to INTB, however INTB is an open-drain and active low. On 927, set register reg_0xC6[5]=1 and 0xC6[0]=1 to configure the INTB.

Dac Tran

SVA APPS

Hi Dac,

To make I2C pass through from uh927 to the touch(slave) connected to uh928EVM, We configured the uh927q registers:

0x07 = slave id (8bit)

0x08 = slave id (8bit)

I2C read/write on the slave failed. Do we still miss something?

Thansk,

Ning

Hi Ning,

Your settings are correct. On 927 enable pass-through on register 0x03 bit[3]=1 and then program 0x07 and 0x08=slave_id. Just to confirm, you host supports I2C clock stretching? Can you also monitor the 928 I2C bus to check if there is any activity when trying to access the touch slave?

Are you able to communicate with 928 from 927 side? On 927, read 0x06 and use that as the target device address.

Dac Tran

SVA APPS

Hi Dac,

We tried to find the slave in following setup and it failed:

HW connection PC - 927EVM - 928EVM - slave device

On 927 System Topology tab we see info:

Before 928EVM connected:

927 device, Reg 03 = 0xda, 06 = 0, 07 = 0, 08 = 0

After 928EVM connected (without slave)

927 and 928 device, 927 Reg 03 = 0xda, 06 = 0x58, 07 = 0x58, 08 = 0xb0

After slave connected to 928EVM

Still only see above: 927 and 928 device, 927 Reg 03 = 0xda, 06 = 0x58, 07 = 0x58, 08 = 0xb0

Write 07 = 0x0a, 08 = 0x0a then refresh the screen. the registers return to above setting: 07 = 0x58, 08 = 0xb0

Why reg 07 and 08 reset to 58 and b0? Do we need to set any reg in 928 for i2c pass-through to slave?

Should we see the slave device in the System Topology tab? If not, how could we verify it with the ALP and EVMs?

Thanks,

Ning

In Addition to the above tests we hooked up another  927 EVM to the 928 (SCL/SDA/GND).

The Hardware is setup as follows  927(0x18)->Rosenberg Connecter cable--> 928 ---> I2C Jumper wires(SCL/SDA/GND) --> 927(0x26).

The two 927 have unique addresses setup from switches on EVK( 0x18 and 0x26(8 bit addresses))

The following are the settingswe have in s/w

927(0x18) -- address 0x03 -- value 0xD8(write)// I2c Passthrough

927(0x18) -- address 0x06 -- value 0x58(read)( Address of Deserializer)

927(0x18) -- address 0x07 -- value 0x26 (write)(Address of second 927Q)

927(0x18) -- address 0x08 -- value 0x26 (write)(Address of second 927Q)

No Settings on 928Q.

We are still unable to talk to the second 927Q.

Please provide us with any settings that we have incorrectly done here or is not clear.

Thanks

JK

We are still getting invalid responses when addressing the remote 927.

This is now resolved . We are able to talk to the 927 connected to i2c bus on the deserializer successfully and read the ID.

Thanks

JK

Hi Ning/JK,

Thanks for the follow up.

Fyi. For the ALP software, the System Topology tab is used to detect devices configured in a repeater application. It is not intended to detect external slaved devices on the remote I2C bus. There is a recursive algorithm that searches for DS90Ux9xx devices connected downstream to each of the 1:3 repeater nodes.  To establish an I2C communication link between the remote slave device, you’ll still need to use 927 registers 0x07-0x08. You can use the Scripting tab to change the software board id to communicate with the external slave.

Dac Tran

SVA APPS