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USB Superspeed Peripherals

New Contributor II

hi
     CyU3PI2cPreamble_t works well if the i2c address is only 2-4 bytes width. but if the register address width is longer than 8 bytes, it is hard to use this structure.
    who know how configure CyU3PI2cPreamble_t if the register length longer then 8 bytes.
for example, if i want to read register address 0x123456789acbde1234,  the value with is 10byes, how to configure?

i tried to separate write/read sequence using following two functions. but cannot work seems due to clock-stretching. who can help here?

CyU3PReturnStatus_t

GW5200_SensorReadNB(uint8_t SlaveAddr, uint8_t *buf, int n)

{

    CyU3PReturnStatus_t apiRetStatus=CY_U3P_SUCCESS;

    CyU3PI2cPreamble_t preamble;

    int i = 0;

  preamble.buffer[0] = SlaveAddr;//0x21;

  preamble.length = 1;

  preamble.ctrlMask = 0x0000;//After the second byte,need to restart the I2C communication

  apiRetStatus = CyU3PI2cReceiveBytes (&preamble, buf, n,0);

  if (apiRetStatus == CY_U3P_SUCCESS)

  {

  IMX390_GW_delay(800);

  }

  else

  CyU3PDebugPrint (4, "GW5200_SensorReadNB failed Error Code = %d\n",apiRetStatus);

#if 1

  CyU3PDebugPrint (4, "read:");

  for(i = 0; i < n; i++)

  {

  CyU3PDebugPrint (4, "0x%x ", buf);

  }

  CyU3PDebugPrint (4, "\r\n");

#endif

  return apiRetStatus;

}

CyU3PReturnStatus_t

GW5200_SensorWriteNB(uint8_t SlaveAddr,uint16_t count, uint8_t *buf)

{

    CyU3PReturnStatus_t apiRetStatus=CY_U3P_SUCCESS;

    CyU3PI2cPreamble_t preamble;

    int i = 0;

  preamble.buffer[0] = SlaveAddr; /* Slave address: Write operation */

  preamble.length = 1;

  preamble.ctrlMask = 0x0000;

  apiRetStatus = CyU3PI2cTransmitBytes (&preamble, buf, count, 0);

  if (apiRetStatus == CY_U3P_SUCCESS)

  {

  IMX390_GW_delay(800); /* known issue for SDK I2C */

  }

  else

  {

  CyU3PDebugPrint (4, "GW5200_SensorWriteNB error!\r\n");

  }

#if 0

  CyU3PDebugPrint (4, "write:");

  for(i = 0; i < count; i++)

  {

  CyU3PDebugPrint (4, "0x%x ", buf);

  }

  CyU3PDebugPrint (4, "\r\n");

#endif

  return apiRetStatus;

}

thanks
xingxing

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1 Solution
Moderator
Moderator

Edited:

Xingxing,

Unfortunately, FX3 cannot write/read to your i2c slave, since it has 11-byte address even the i2c slave supports clock stretching.

The I2C block on FX3 can handle upto the preamble of 64 bits (8 bytes). This preamble includes the slave address, R/W command, possible internal address and repeated start command. Preamble Values more than 8 bytes are not supported.

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4 Replies
Moderator
Moderator

The I2C block on FX3 can handle upto the preamble of 64 bits (8 bytes). This preamble includes the slave address, R/W command, possible internal address and repeated start command. Preamble Values more than 8 bytes are not supported.

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New Contributor II

thanks your reply.
the i2c slave deivce support clock-stretching, is there any special setting for fx3 to support clock-stretching device?

thanks
xingxing

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New Contributor II

hi,
if i want this process, how to configure preamble ?
START-0xDA-0x33-0x05-0x00-0x00-0x00-0xa1-0x00-0x80-0x01-0x01-0xa2-STOP-START-0xDB-(read)0x33-0x41-0x02.....0x78-STOP

thanks
xingxing

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Moderator
Moderator

Edited:

Xingxing,

Unfortunately, FX3 cannot write/read to your i2c slave, since it has 11-byte address even the i2c slave supports clock stretching.

The I2C block on FX3 can handle upto the preamble of 64 bits (8 bytes). This preamble includes the slave address, R/W command, possible internal address and repeated start command. Preamble Values more than 8 bytes are not supported.

View solution in original post

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