This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS90UB949-Q1: DS90UB949-Q1 interrupt latency

Part Number: DS90UB949-Q1

Hello team,

I am using a DS90UB949-Q1-based EVK kit for my test. My setup is such that, I have a device present at the Deser (UB948) side which is connected to the Deser using I2C and a GPIO pin is also input to the Deser. The SerDes are connected using LVDS cable for communication. I am having an I2C master device at the Ser device which is connected to the Ser via I2C pins. 

Now coming back to the problem, the device which is present at the Deser side gives the interrupt to the Deser at GPIO0, and then this interrupt is back channeled to the Ser and then back to the I2C master device. I have enabled the 0xC6 register address as 0x21 to enable the interrupt on Serializer. So, whenever the interrupt arrives, the INTB pin is low and I read from the I2C master device that the interrupt has arrived, and then again clear the interrupt by reading the 0xC7 register of the Serializer, now the problem is that I am receiving the interrupt i.e., getting INTB to pin low after 30ms, which should be arrived to the Serializer side at 15ms because the device generates the interrupt at 15ms, so I am asking that if there is any delay with the BC so that I am receiving the interrupt by so much delay. Can you tell me how can I improve this delay/ latency in the interrupt arrival at the Serializer INTB pin?

Thank you.

Regards,
Vivek Karna

  • Hi Vivek, 

    Can you share your register configurations for the SER and DES? A block diagram of the setup would also be helpful. 

    Just as a note that I will be away for training 11/7-11/9 and responses may be delayed. 

    Best,

    Shu

  • Hello Shu,

    Sorry for the late reply. I have been busy with some other work meanwhile.

    Please find the register dump of Ser and Deser below.

    [REGISTERS]
    Device = ALP Nano 1 - DS90UB948, Connector 1
    Comments = "Deserializer Register"
    Date = 11/22/2022
    Time = 15:37:37
    Reg = 0,0x0000,0x58
    Reg = 0,0x0001,0x04
    Reg = 0,0x0002,0x00
    Reg = 0,0x0003,0xF0
    Reg = 0,0x0004,0xFE
    Reg = 0,0x0005,0x1E
    Reg = 0,0x0006,0x00
    Reg = 0,0x0007,0x1C
    Reg = 0,0x0008,0x00
    Reg = 0,0x0009,0x00
    Reg = 0,0x000A,0x00
    Reg = 0,0x000B,0x00
    Reg = 0,0x000C,0x00
    Reg = 0,0x000D,0x00
    Reg = 0,0x000E,0x00
    Reg = 0,0x000F,0x00
    Reg = 0,0x0010,0x00
    Reg = 0,0x0011,0x00
    Reg = 0,0x0012,0x00
    Reg = 0,0x0013,0x00
    Reg = 0,0x0014,0x00
    Reg = 0,0x0015,0x00
    Reg = 0,0x0016,0x00
    Reg = 0,0x0017,0x00
    Reg = 0,0x0018,0x00
    Reg = 0,0x0019,0x01
    Reg = 0,0x001A,0x00
    Reg = 0,0x001B,0xF4
    Reg = 0,0x001C,0x3B
    Reg = 0,0x001D,0x13
    Reg = 0,0x001E,0x00
    Reg = 0,0x001F,0x00
    Reg = 0,0x0020,0x00
    Reg = 0,0x0021,0x00
    Reg = 0,0x0022,0x42
    Reg = 0,0x0023,0x20
    Reg = 0,0x0024,0x08
    Reg = 0,0x0025,0x00
    Reg = 0,0x0026,0x14
    Reg = 0,0x0027,0x26
    Reg = 0,0x0028,0x10
    Reg = 0,0x0029,0x00
    Reg = 0,0x002A,0x00
    Reg = 0,0x002B,0x00
    Reg = 0,0x002C,0x00
    Reg = 0,0x002D,0x00
    Reg = 0,0x002E,0x00
    Reg = 0,0x002F,0x00
    Reg = 0,0x0030,0x00
    Reg = 0,0x0031,0x00
    Reg = 0,0x0032,0x90
    Reg = 0,0x0033,0x25
    Reg = 0,0x0034,0x01
    Reg = 0,0x0035,0x00
    Reg = 0,0x0036,0x00
    Reg = 0,0x0037,0x88
    Reg = 0,0x0038,0x00
    Reg = 0,0x0039,0x00
    Reg = 0,0x003A,0x00
    Reg = 0,0x003B,0x03
    Reg = 0,0x003C,0x20
    Reg = 0,0x003D,0xE0
    Reg = 0,0x003E,0x23
    Reg = 0,0x003F,0x00
    Reg = 0,0x0040,0x43
    Reg = 0,0x0041,0x03
    Reg = 0,0x0042,0x03
    Reg = 0,0x0043,0x00
    Reg = 0,0x0044,0x60
    Reg = 0,0x0045,0x88
    Reg = 0,0x0046,0x00
    Reg = 0,0x0047,0x00
    Reg = 0,0x0048,0x0F
    Reg = 0,0x0049,0x00
    Reg = 0,0x004A,0x00
    Reg = 0,0x004B,0x03
    Reg = 0,0x004C,0x00
    Reg = 0,0x004D,0x00
    Reg = 0,0x004E,0x63
    Reg = 0,0x004F,0x00
    Reg = 0,0x0050,0x03
    Reg = 0,0x0051,0x10
    Reg = 0,0x0052,0x00
    Reg = 0,0x0053,0x01
    Reg = 0,0x0054,0x80
    Reg = 0,0x0055,0x00
    Reg = 0,0x0056,0x00
    Reg = 0,0x0057,0x00
    Reg = 0,0x0058,0x00
    Reg = 0,0x0059,0x7F
    Reg = 0,0x005A,0x20
    Reg = 0,0x005B,0x20
    Reg = 0,0x005C,0x00
    Reg = 0,0x005D,0x00
    Reg = 0,0x005E,0x00
    Reg = 0,0x005F,0x00
    Reg = 0,0x0060,0x00
    Reg = 0,0x0061,0x00
    Reg = 0,0x0062,0x00
    Reg = 0,0x0063,0x00
    Reg = 0,0x0064,0x10
    Reg = 0,0x0065,0x00
    Reg = 0,0x0066,0x00
    Reg = 0,0x0067,0x00
    Reg = 0,0x0068,0x00
    Reg = 0,0x0069,0x00
    Reg = 0,0x006E,0x01
    Reg = 0,0x006F,0x00
    Reg = 0,0x0070,0x00
    Reg = 0,0x0071,0x00
    Reg = 0,0x0072,0x00
    Reg = 0,0x0073,0x07
    Reg = 0,0x0074,0x07
    Reg = 0,0x0075,0x08
    Reg = 0,0x0076,0x00
    Reg = 0,0x0077,0x00
    Reg = 0,0x0078,0x00
    Reg = 0,0x0079,0x00
    Reg = 0,0x007A,0x00
    Reg = 0,0x007B,0x5D
    Reg = 0,0x007C,0x02
    Reg = 0,0x0080,0x00
    Reg = 0,0x0081,0x00
    Reg = 0,0x0082,0x00
    Reg = 0,0x0083,0x00
    Reg = 0,0x0084,0x00
    Reg = 0,0x0090,0x00
    Reg = 0,0x0091,0x00
    Reg = 0,0x0092,0x00
    Reg = 0,0x0093,0x00
    Reg = 0,0x0094,0x00
    Reg = 0,0x0098,0x00
    Reg = 0,0x0099,0x00
    Reg = 0,0x009A,0x00
    Reg = 0,0x009B,0x00
    Reg = 0,0x009C,0x00
    Reg = 0,0x009D,0x00
    Reg = 0,0x009E,0x00
    Reg = 0,0x009F,0x00
    Reg = 0,0x00C0,0x00
    Reg = 0,0x00C1,0x00
    Reg = 0,0x00C3,0x00
    Reg = 0,0x00C4,0x00
    Reg = 0,0x00C5,0x00
    Reg = 0,0x00C8,0xC0
    Reg = 0,0x00C9,0x00
    Reg = 0,0x00CA,0x00
    Reg = 0,0x00CB,0x00
    Reg = 0,0x00CC,0x00
    Reg = 0,0x00E0,0x00
    Reg = 0,0x00E1,0x00
    Reg = 0,0x00E2,0x00
    Reg = 0,0x00E3,0x00
    Reg = 0,0x00E8,0x00
    Reg = 0,0x00E9,0x00
    Reg = 0,0x00EA,0x00
    Reg = 0,0x00F0,0x5F
    Reg = 0,0x00F1,0x55
    Reg = 0,0x00F2,0x42
    Reg = 0,0x00F3,0x39
    Reg = 0,0x00F4,0x34
    Reg = 0,0x00F5,0x38
    Reg = 0,0x00F6,0x00
    Reg = 0,0x00F8,0x00
    Reg = 0,0x00F9,0x00
    
    [REGISTERS]
    Device = ALP Nano 1 - DS90UB949, Connector 1
    Comments = "Serializer Register"
    Date = 11/22/2022
    Time = 15:37:13
    Reg = 0,0x0000,0x1C
    Reg = 0,0x0001,0x00
    Reg = 0,0x0003,0xDA
    Reg = 0,0x0004,0x80
    Reg = 0,0x0005,0x00
    Reg = 0,0x0006,0x58
    Reg = 0,0x0007,0x24
    Reg = 0,0x0008,0x24
    Reg = 0,0x0009,0x00
    Reg = 0,0x000A,0xBE
    Reg = 0,0x000B,0x01
    Reg = 0,0x000C,0x17
    Reg = 0,0x000D,0x27
    Reg = 0,0x000E,0x10
    Reg = 0,0x000F,0x09
    Reg = 0,0x0010,0x01
    Reg = 0,0x0011,0x00
    Reg = 0,0x0012,0x02
    Reg = 0,0x0013,0xC8
    Reg = 0,0x0014,0x00
    Reg = 0,0x0015,0x01
    Reg = 0,0x0016,0x02
    Reg = 0,0x0017,0x1E
    Reg = 0,0x0018,0x7F
    Reg = 0,0x0019,0x7F
    Reg = 0,0x001A,0x00
    Reg = 0,0x001B,0x00
    Reg = 0,0x001C,0x00
    Reg = 0,0x001D,0x00
    Reg = 0,0x001E,0x05
    Reg = 0,0x001F,0xF7
    Reg = 0,0x0020,0x0B
    Reg = 0,0x0021,0x00
    Reg = 0,0x0022,0x25
    Reg = 0,0x0023,0x00
    Reg = 0,0x0024,0x00
    Reg = 0,0x0025,0x00
    Reg = 0,0x0026,0x00
    Reg = 0,0x0027,0x00
    Reg = 0,0x0028,0x01
    Reg = 0,0x0029,0x20
    Reg = 0,0x002A,0x20
    Reg = 0,0x002B,0xB8
    Reg = 0,0x002C,0x00
    Reg = 0,0x0030,0x00
    Reg = 0,0x0031,0x00
    Reg = 0,0x0032,0x00
    Reg = 0,0x0033,0x00
    Reg = 0,0x0034,0x00
    Reg = 0,0x0035,0x00
    Reg = 0,0x0036,0x00
    Reg = 0,0x0037,0x00
    Reg = 0,0x0038,0x00
    Reg = 0,0x0039,0x00
    Reg = 0,0x003A,0x00
    Reg = 0,0x003B,0x00
    Reg = 0,0x003C,0x00
    Reg = 0,0x003D,0x00
    Reg = 0,0x003E,0x00
    Reg = 0,0x003F,0x00
    Reg = 0,0x0040,0x14
    Reg = 0,0x0041,0x49
    Reg = 0,0x0042,0x00
    Reg = 0,0x0043,0x00
    Reg = 0,0x0044,0x80
    Reg = 0,0x0045,0x00
    Reg = 0,0x0046,0x00
    Reg = 0,0x0047,0x00
    Reg = 0,0x0048,0x01
    Reg = 0,0x0049,0x68
    Reg = 0,0x004A,0x01
    Reg = 0,0x004B,0xB0
    Reg = 0,0x004C,0x04
    Reg = 0,0x004D,0x00
    Reg = 0,0x004E,0x00
    Reg = 0,0x004F,0x00
    Reg = 0,0x0050,0x97
    Reg = 0,0x0051,0xA1
    Reg = 0,0x0052,0x1E
    Reg = 0,0x0053,0x00
    Reg = 0,0x0054,0x28
    Reg = 0,0x0055,0x4C
    Reg = 0,0x0056,0x2A
    Reg = 0,0x0057,0x00
    Reg = 0,0x0058,0x00
    Reg = 0,0x0059,0x00
    Reg = 0,0x005A,0xCD
    Reg = 0,0x005B,0x20
    Reg = 0,0x005C,0x02
    Reg = 0,0x005D,0x06
    Reg = 0,0x005E,0x44
    Reg = 0,0x005F,0x9E
    Reg = 0,0x0060,0x22
    Reg = 0,0x0061,0x02
    Reg = 0,0x0062,0x00
    Reg = 0,0x0064,0x10
    Reg = 0,0x0065,0x00
    Reg = 0,0x0066,0x00
    Reg = 0,0x0067,0x00
    Reg = 0,0x0068,0x00
    Reg = 0,0x0069,0x00
    Reg = 0,0x006A,0x00
    Reg = 0,0x006B,0x00
    Reg = 0,0x006C,0x00
    Reg = 0,0x0070,0x00
    Reg = 0,0x0071,0x00
    Reg = 0,0x0072,0x00
    Reg = 0,0x0073,0x00
    Reg = 0,0x0074,0x00
    Reg = 0,0x0075,0x00
    Reg = 0,0x0076,0x00
    Reg = 0,0x0077,0x00
    Reg = 0,0x0078,0x00
    Reg = 0,0x0079,0x00
    Reg = 0,0x007A,0x00
    Reg = 0,0x007B,0x00
    Reg = 0,0x007C,0x00
    Reg = 0,0x007D,0x00
    Reg = 0,0x0080,0x00
    Reg = 0,0x0081,0x00
    Reg = 0,0x0082,0x00
    Reg = 0,0x0083,0x00
    Reg = 0,0x0084,0x00
    Reg = 0,0x0090,0x00
    Reg = 0,0x0091,0x00
    Reg = 0,0x0092,0x00
    Reg = 0,0x0093,0x00
    Reg = 0,0x0094,0x00
    Reg = 0,0x0098,0x00
    Reg = 0,0x0099,0x00
    Reg = 0,0x009A,0x00
    Reg = 0,0x009B,0x00
    Reg = 0,0x009C,0x00
    Reg = 0,0x009D,0x00
    Reg = 0,0x009E,0x00
    Reg = 0,0x009F,0x00
    Reg = 0,0x00A0,0x00
    Reg = 0,0x00A1,0x00
    Reg = 0,0x00A2,0x00
    Reg = 0,0x00A3,0x00
    Reg = 0,0x00C0,0x00
    Reg = 0,0x00C1,0x00
    Reg = 0,0x00C2,0xA8
    Reg = 0,0x00C3,0x00
    Reg = 0,0x00C4,0x68
    Reg = 0,0x00C5,0x00
    Reg = 0,0x00C6,0x21
    Reg = 0,0x00C7,0x00
    Reg = 0,0x00C8,0xC0
    Reg = 0,0x00C9,0x00
    Reg = 0,0x00CA,0x00
    Reg = 0,0x00CB,0x00
    Reg = 0,0x00CC,0x00
    Reg = 0,0x00CE,0xFF
    Reg = 0,0x00D0,0x00
    Reg = 0,0x00D1,0x00
    Reg = 0,0x00D2,0x00
    Reg = 0,0x00D3,0x00
    Reg = 0,0x00E0,0x00
    Reg = 0,0x00E1,0x00
    Reg = 0,0x00E2,0xA8
    Reg = 0,0x00E3,0x00
    Reg = 0,0x00E4,0x68
    Reg = 0,0x00E5,0x38
    Reg = 0,0x00E6,0x21
    Reg = 0,0x00E7,0x00
    Reg = 0,0x00F0,0x5F
    Reg = 0,0x00F1,0x55
    Reg = 0,0x00F2,0x42
    Reg = 0,0x00F3,0x39
    Reg = 0,0x00F4,0x34
    Reg = 0,0x00F5,0x39
    Reg = 0,0x00F6,0x00
    Reg = 0,0x00F8,0x00
    Reg = 0,0x00F9,0x00
    


    Please share your thoughts on where can be the issue in the delay of the back channel data.

    Thanks & Regards,
    Vivek Karna


  • Hi Vivek, 

    Due to the upcoming Thanksgiving Holiday in the US, responses will be delayed. I will provide an update/feedback by 11/29. 

    Best,

    Shu

  • Hi Vivek, 

    I am a little confused, are you not using INTB_IN on the 948? The INTB on the 949 and the procedure you highlighted with setting register 0xC6 on the Serializer is applicable with the interrupt is set on the INTB_IN pin. 

    the device which is present at the Deser side gives the interrupt to the Deser at GPIO0, and then this interrupt is back channeled to the Ser and then back to the I2C master device.

    Can you walk me through the procedure/sequence you are using?

    Best,

    Shu