DP83822I: compliance testing - 10BASE-T 0x0027 does nothing

Lukas Maier

Part Number: DP83822I

Hello together,

I have a problem running the compliance test on the DP83822I for the 10BASE-T Standard, since the 0x0027 register isn't doing anything for me.

I'm probably missing a instruction to enable this function, or the wrapper we wrote to write to the extended register isn't working correctly.

I'll try bypassing the function tomorrow.

First I followed the SNLA266 for the tests since this manual sneaks around the use of 0x0027, but for a specific test my LeCroy Scope asks for a all Ones code.

Which should correspond to a value of 0x0013 for register 0x0027, this doesn't work.

/*Start of Test modes*/
        // snla266 A.3 10BASE-Te Standsard Test Script MDI works but only with the 0x0016 not with 0x0027
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x001F, 0x8000); // software reset (clears register
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0000, 0x0100); // programs DUT to 10BASE-T mode
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0019, 0x0021); // programs DUT to Forced MDI mode
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0016, 0x7108); //programs DUT to generate data and enables analog loopback mode
        //HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0027, 0x0019);   // this should never work since 0x0027 is bigger than the biggest standard register (0x001F) 
        //HalEthInitStatus = writeExtRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0027, 0x0019); // this doesn't work I don't know why
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x001F, 0x4000); // digital reset (doesn’t clear reg
        // end
        HAL_Delay(1000);
        // snla266 A.3 10BASE-Te Standard Link Pulse works
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x001F, 0x8000); // software reset (clears register
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0000, 0x0100); // programs DUT to 10BASE-T mode
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0019, 0x0021); // programs DUT to Forced MDI mode
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x001F, 0x4000); // digital reset (doesn’t clear reg
        // end
        HAL_Delay(1000);
        // snla266 A.3 10BASE-Te All Ones doesn't work
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x001F, 0x8000); // software reset (clears register
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0000, 0x0100); // programs DUT to 10BASE-T mode
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0019, 0x0021); // programs DUT to Forced MDI mode  
        HalEthInitStatus = writeExtRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x0027, 0x0013);
        HalEthInitStatus = HAL_ETH_WritePHYRegister(&LWIP_MOD_ETHIF_EtherHandle, ETH_PHY_ADDRESS, 0x001F, 0x4000); // digital reset (doesn’t clear reg
        HAL_Delay(1000);

Can anybody tell me the secret to the 0x0027 register ?

Thanks in advance

over 2 years ago

0 Rahul over 2 years ago

TI__Expert 8721 points

Hi Lukas,

Register 0x0027 is in extended register space and you cannot access it directly. Please follow the Extended Register Space process according to Section 8.4.2.1 to write or read this register:
8.4.2.1 Extended Register Space Access
https://www.ti.com/lit/ds/symlink/dp83822i.pdf?ts=1669830898442&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDP83822I

Regards,
Rahul

0 Lukas Maier over 2 years ago in reply to Rahul

Prodigy 91 points

Hi Rahul,

as far as I can tell our writeExtRegister() function is doing what is specified in the datasheet. And setting the LEDs to a specific behavior works just fine.

...
#define PHY_REGCR (0x000D)
#define PHY_REGCR_MMD31 (0x001F) /**< DEVAD = 11111 (general MMD register accesses) */
#define PHY_REGCR_CMD_ADDRESS (0x0000) /**< CMD = 00 (address) */
#define PHY_REGCR_CMD_DATA_NO_POST_INCREMENT (0x4000) /**< CMD = 01 (Data, no post increment) */
#define PHY_ADDAR (0x000E)
...
static HAL_StatusTypeDef writeExtRegister(ETH_HandleTypeDef *ETHHandle, uint32_t PHYAddr, uint16_t PHYReg, uint32_t RegValue)
{
    HAL_StatusTypeDef HalEthStatus = HAL_OK;

    HalEthStatus |= HAL_ETH_WritePHYRegister(ETHHandle, PHYAddr, PHY_REGCR, (PHY_REGCR_CMD_ADDRESS | PHY_REGCR_MMD31));
    HalEthStatus |= HAL_ETH_WritePHYRegister(ETHHandle, PHYAddr, PHY_ADDAR, PHYReg); /* address to write to */
    HalEthStatus |= HAL_ETH_WritePHYRegister(ETHHandle, PHYAddr, PHY_REGCR, (PHY_REGCR_CMD_DATA_NO_POST_INCREMENT | PHY_REGCR_MMD31));

    /* Write value into indirectly addressed register */
    HalEthStatus |= HAL_ETH_WritePHYRegister(ETHHandle, PHYAddr, PHY_ADDAR, RegValue);

    return HalEthStatus;
}
...

Any other suggestions why it might not work ?

0 Rahul over 2 years ago in reply to Lukas Maier

TI__Expert 8721 points

Hi Lukas,

Let me try to replicate this in our lab and update you with my results.

I have few other customer issues to debug this week, I will get back to you early next week.

Thanks,
Rahul

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DP83822I: compliance testing - 10BASE-T 0x0027 does nothing