DS90UB936-Q1: synchronous operation

Hi Vineeth,

1. In the 935, you can do either of the following:
   1. Configure the strap resistors at the MODE pin to enable CSI-2 synchronous operation at start-up.
   2. If you want to use register setup, then perform the following:
      1. Set reg 0x03[4] = 1
      2. Set reg 0x03[2:0] = 000
2. In the 936, you can do either of the following:
   1. Configure the strap resistors at the MODE pin to enable CSI-2 synchronous operation at start-up.
   2. If you want to use register setup, then perform the following:
      
      1. Set reg 0x58[2:0] = 110
      2. Set reg 0x6D[1:0] = 00

Best,

Justin Phan

clock out of serializer should be 24 MHz for Camera sensor .can you please share the register configuration of serializer for that? I found some register related to clock out ( M/N value configure register) 

Hi Vineeth,

For this, you can refer to Section 7.4.1.5 Configuring CLK_OUT in the 935 datasheet. Use equation (1) to calculate your CLK_OUT:

The HS_CLK_DIV, M, and N values are set in registers 0x06 and 0x07. By default, registers 0x06 and 0x07 are set such that the REFCLK applied at the 936 will be the same as the CLK_OUT at the 935. See the example calculation below (REFCLK = 25MHz):

FC = Forward Channel Data Rate = f x 160 = 25MHz * 160 = 4GHz (See Table 7-6 in the 935 datasheet for this equation)

M = 1 (default)

HS_CLK_DIV = 4 (default)

N = 40 (default)

CLK_OUT = 25MHz

If you apply a 25MHz at the 936 side, then you would need to adjust the 0x06 and 0x07 register values in order to get a 24MHz CLK_OUT at the 935 side.

FC = Forward Channel Data Rate = f x 160 = 25MHz * 160 = 4GHz (See Table 7-6 in the 935 datasheet for this equation)  

M = 1 (default)

HS_CLK_DIV = 4 (default)

N = 42 (set reg 0x07 = 0x2A)

CLK_OUT = 23.81MHz = ~24MHz

Best,

Justin Phan

Hi Justin,

In our custom hardware, Deserializer  is configured as non synchronous mode ( please refer the attached figure, MODE NO.0 CSI-2 non-synchronous back channel) and seializer is configured as non synchronuous internal clock mode.  is it possible to configure deserializer and serializer operate in synchronous mode without modifying hardware configuration?

Hi,

we changed the deserializer register 0x58=5e and serializer register 0x03=0x0 and 0x32=29( to enable auto acknowledge) when we configuring cmos through back channel, we got i2c writer error. can you please provide the proper configuration procedure to avoid i2c write error in our case?

Hi Vineeth,

Refer to Section 7.5.3 Remote Slave Operation in the 936 datasheet for more instructions on how to configure the 936 in order to perform a remote write from the DES to a connected SER. Here is a brief summary:

1. On the 936, set reg 0x4C[4] and reg 0x4C[1:0] to select which RX port you would like to enable I2C read/write commands.
2. The I2C address of the selected RX port Serializer will be shown in reg 0x5B.
3. Set reg 0x58[6] = 1, to enable I2C_PASS_THROUGH.

Now, the 936 will be able to propagate messages to I2C addresses it recognizes, such as the I2C address of the connected 935 Serializer.

After that, then you can start to configure the devices for Synchronous Mode. Make sure to configure the 935 SER registers first, before changing the 936 DES registers.

Best,

Justin Phan 

Hi Justin,

We followed the above step. but still we got some i2c error in the camera  side. please see the configuration sequence.

0x4c =0x01

0x58=0x5a

0x5c=0x30

after that we configured the serializer register

0x03=0x00 // synchronous mode

0x32=0x29// enable auto-acknowledgement

after that we configured deserializer

0x20, 0x20,
0x21, 0x81,
0x33, 0x21,
0x6d, 0x7c,
0x1f, 0x02,
0x4c, 0x01,
0x70, 0x1e,
0x7c, 0xc0,
0x0c, 0x83,
0x58, 0x5e,// deserializer synchronous mode configuration
0x5c, 0x30,
0x5d, 0xc0,
0x65, 0xc0,
0x5e, 0x40,
0x66, 0x40,
0x5f, 0x58,
0x67, 0x58,

then we configured gpio of serializerfor cmos 

0x02, 0x13,// 2lane mipi configuration
0x0e, 0x1e,
0x0d, 0x00,
0x0d, 0x01,

after that we configured cmos register.

we found that i2cwrite error in the cmos side.can you please provide the solution for the above issue?

is it possible to run deserializer in synchronous mode(50Mbps) and serializer in non synchronous clock mode(10Mbps) combination?

Hi Vineeth,

It is not possible to run the DES in Sync Mode and the SER in Non-Sync Mode. Once you change the mode, each device will be configured for a different back channel rate. And as a result, you will not be able to communicate with the remote SER anymore. This is why you should configure the remote SER to Synchronous Mode first. And then configure your local DES to Synchronous Mode to match. 

In the 935 SER, make sure to set the MODE_OV bit to 1 (reg 0x03[4] = 1). This allows your register configurations to override the strap resistor configurations. Bits 2:0 in reg 0x03 set the new Mode configuration and should be 000 for CSI-2 Synchronous Mode.

Also, in the 935, could you try to disable AUTO_ACK_ALL (reg 0x32 = 0x09)?

Best,

Justin Phan

Hi Justin,

We followed the above step. but still we got some i2c error in the serializer side. please see the configuration sequence.

0x4c =0x01

0x58=0x5a

0x5c=0x30

after that we configured the serializer register

0x03=0x10 // synchronous mode--- In this step we got i2c write error.  [result=Failure ch=0x5 addr=30 reg=0x03 data=0x10
[ti935_write_reg][533] ti93XX_ov2310_i2c_send Failed] 

but Remaining registers are  properly configured without any i2c write error . what does it indicate?

0x32=0x09// enable auto-acknowledgement

after that we configured deserializer

0x20, 0x20,
0x21, 0x81,
0x33, 0x21,
0x6d, 0x7c,
0x1f, 0x02,
0x4c, 0x01,
0x70, 0x1e,
0x7c, 0xc0,
0x0c, 0x83,
0x58, 0x5e,// deserializer synchronous mode configuration
0x5c, 0x30,
0x5d, 0xc0,
0x65, 0xc0,
0x5e, 0x40,
0x66, 0x40,
0x5f, 0x58,
0x67, 0x58,

then we configured gpio of serializerfor cmos 

0x02, 0x13,// 2lane mipi configuration
0x0e, 0x1e,
0x0d, 0x00,
0x0d, 0x01,

Hi Vineeth,

After configuring the I2C_PASS_THROUGH on the 936, are you able to successfully read and write to other registers on the 935?

Could you try to read the value of the 0x03 register in the 935, before you send an I2C write command? And then make sure you are only making changes to bits 4 and [2:0] in the 0x03 register. 

Best,

Justin Phan

Hi Justin, 

We have modified our serialized board .now it is working in synchronous mode.but still our deserializer board in non synchronous mode.can you please provide the configuration sequence in order to operate both in synchronous mode? I think we need to change 0x58 register configuration to 50Mbps.can you please confirm?