DS125DF1610: Configuration for 10G speed

Hi Lucas,

Thanks for looking into this. I want to clarify the customer's scheme as it was not clearly shown on my initial question.

The customer wants to use DS125DF1610 as a source of the PRBS sequence. The diagram is shown in the figure below. LMH2581, frequency 2.5 GHz, is used as a reference signal. At the output of the DS125DF1610, they need to get a speed of 10G. But unfortunately on this case, the customer is only getting 5G.

Kind Regards,

Jejomar

Hello Lucas,

Unfortunately, according to your recommendations, customer was not able to achieve 10G speed.

They check the speed on an Anritsu MP2100B oscilloscope. Ran 10G speed (PRBS-31) from the device, set a similar mode on the oscilloscope and see that there is no positive result.

On the other hand, if they switch the oscilloscope to 5G mode (PRBS-31), the result is positive. That is, the DS125DF1610 generates 5G, not 10G as required.

Below I will provide the initialization code, we would appreciate if you can help us pinpoint where the error is located.

void set_all_channel_10G( void )
{ // ff ff 14 ff ff 02 ff ff 2f ff fc fd
uint8_t data[12]={0x01,0x03,0x00,0x01,0x00,0x20,0x01,0x03,0xA6,0x01,0x00,0x01};
// Write to the channel regs
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[0],1,10);
HAL_Delay(100);
// Write to the channel regs (broadcast)
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[1],1,10);
HAL_Delay(110);
// ??
HAL_I2C_Mem_Write(&hi2c3,0x30,0x14,1,&data[2],1,10);
HAL_Delay(250);
// Turn off broadcast write
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[3],1,10);
HAL_Delay(100);
// Write to the share regs
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[4],1,10);
HAL_Delay(100);
// Freq 125 MHz
HAL_I2C_Mem_Write(&hi2c3,0x30,0x02,1,&data[5],1,10);
HAL_Delay(100);
// Write to the channel regs
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[6],1,100);
HAL_Delay(100);
// Write to the channel regs (broadcast)
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[7],1,100);
HAL_Delay(250);
//CTLE - off, EN_FLD_C

//CTLE - off, EN_FLD_CHECK = 1, EN_PPM_CHECK = 1, rate - 10 Gbps
HAL_I2C_Mem_Write(&hi2c3,0x30,0x2F,1,&data[8],1,100);
HAL_Delay(250);
// Write to the channel regs( not broadcast)
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[9],1,100);
HAL_Delay(100);
// Channels 0 - 7 switch off
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFC,1,&data[10],1,100);
HAL_Delay(100);
// Channel 8 - switch on
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFD,1,&data[11],1,100);
HAL_Delay(500);


uint8_t data3[3]={0x03,0x04,0x01};
// Write to the channel regs (broadcast)
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data3[0],1,10);
HAL_Delay(100);
// 0x09[2] = 1 enable bit to override divsel
HAL_I2C_Mem_Write(&hi2c3,0x30,0x09,1,&data3[1],1,10);
HAL_Delay(170);
// Turn off broadcast write
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data3[2],1,10);
HAL_Delay(500);


uint8_t data4[3]={0x03,0x00,0x01};
// Write to the channel regs (broadcast)
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data4[0],1,10);
HAL_Delay(70);
// PDIQ

// PDIQ_SEL_DIV, divide by 1 (bits 4-6 = 0b000)
HAL_I2C_Mem_Write(&hi2c3,0x30,0x18,1,&data4[1],1,10);
HAL_Delay(170);
// Turn off broadcast write
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data4[2],1,10);
HAL_Delay(100);

uint8_t data5[3]={0x03,0x00,0x01};
// Write to the channel regs (broadcast)
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data5[0],1,10);
HAL_Delay(100);
// SINGLE_BIT_LIMIT_CHECK_ON - switch off
HAL_I2C_Mem_Write(&hi2c3,0x30,0x0C,1,&data5[1],1,10);
HAL_Delay(170);
// Turn off broadcast write
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data5[2],1,10);
HAL_Delay(500);
}

Kind Regards,

Jejomar

Hi Jejomar,

Before I fully review this register sequence, can you clarify each of the parameters? I can infer what some of the parameters are, but can you share what the others represent? Are masks being used or is the register value being written completely to each register address?

HAL_I2C_Mem_Write(i2c bus, device address, register address, ??, register value, ??, ??)

Example from initialization code: HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[0],1,10);

Best,

Lucas

Hello Lucas,

Below are parameters of the function for accessing DS125DF1610

Example from initialization code:
HAL_I2C_Mem_Write(&hi2c3,0x30,0xFF,1,&data[0],1,10);

Here:
&hi2c3 - I2C Bus
0x30 - I2C device address
0xFF - register address
1 - memAddSize size of internal memory address
&data[0] - register value
1 - size amount of data to be sent
10 - timeout (in ms)

Just in case, I will also give the standard definition of this function from the HAL libraries.

/**
* @brief Write an amount of data in blocking mode to a specific memory address
* @param hi2c Pointer to a I2C_HandleTypeDef structure that contains
* the configuration information for the specified I2C.
* @param DevAddress Target device address
* @param MemAddress Internal memory address
* @param MemAddSize Size of internal memory address
* @param pData Pointer to data buffer
* @param Size Amount of data to be sent
* @param Timeout Timeout duration
* @retval HAL status
*/
HAL_StatusTypeDef HAL_I2C_Mem_Write(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint16_t MemAddress, uint16_t MemAddSize, uint8_t *pData, uint16_t Size, uint32_t Timeout)
{
}

Kind Regards,

Jejomar