SNLU302 March   2025 DS320PR810 , DS320PR822

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Access Methods
    1. 1.1 Register Programming Through SMBus
    2. 1.2 Device Configuration Through External EEPROM
  5. 2Register Map Overview
    1. 2.1 Share Registers
    2. 2.2 Channel Registers
  6. 3Equalization Control Settings
  7. 4CTLE Index and Flat Gain Selection Matrix
  8. 5Example Programming Sequences
    1. 5.1 Set CTLE Gain Level
    2. 5.2 Set CTLE Flat Gain Level
    3. 5.3 Set PD Control
    4. 5.4 Set SEL Input (DS320PR822)
  9. 6References

5.4 Set SEL Input (DS320PR822)

Note: This section applies to the DS320PR822 only.

On the DS320PR822, the inputs SEL0 and SEL1 can be manually set to select the cross-point data path for the respective channel banks. Note that the SEL0 pin configures the cross-point for channels 0-3 and the SEL1 pin configures the cross-point for channels 4-7. Table 5-5 shows an example sequence for setting the SELx pin on Bank 0 and Bank 1 to the straight data path or cross-point data path.

Table 5-5 Sequence to set Cross-Point SEL Pins by Register Bank
Step Register Set Operation Register Address
[HEX]		 Register Value
[HEX]		 Write Mask
[HEX]		 Comment
1 Bank 0 Share Write 0xEE 0x44 0x44 Set SEL0 override bit for all Bank 0 channels.
2 Bank 0 Share Write 0xEF 0x00 0x44 Set SEL0 bit low for all Bank 0 channels to select straight data path.
0x44 0x44 Set SEL0 bit high for all Bank 0 channels to select cross-point data path.
3 Bank 1 Share Write 0xEE 0x44 0x44 Set SEL1 override bit for all Bank 0 channels.
4 Bank 1 Share Write 0xEF 0x00 0x44 Set SEL1 bit low for all Bank 0 channels to select straight data path.
0x44 0x44 Set SEL1 bit high for all Bank 0 channels to select cross-point data path.

Assuming 0x18 and 0x19 are the SMBus addresses for Banks 0 and 1, respectively, the following is the XML batch script of the cross-point data path selection sequence in Table 5-5:

<i2c_write addr="0x18" count="0" radix"16">EE 44</i2c_write>
<i2c_write addr="0x18" count="0" radix"16">EF 44</i2c_write>
<i2c_write addr="0x19" count="0" radix"16">EE 44</i2c_write>
<i2c_write addr="0x19" count="0" radix"16">EF 44</i2c_write>