4.7. SFP28 ..................................................................................................................................... 67
4.8. SFP+ ....................................................................................................................................... 67
5. Sub-system ............................................................................................................................................ 68
5.1. Management PHY (BCM54616S) .......................................................................................... 68
5.2. Configurations of MGMT PHY (BCM54616S) ........................................................................ 68
5.3. POR of MGMT PHY (BCM54616S) ......................................................................................... 68
5.4. I2C ......................................................................................................................................... 68
5.5. UART ...................................................................................................................................... 72
5.6. USB ........................................................................................................................................ 73
5.7. Interrupt ................................................................................................................................ 73
5.8. JTAG ...................................................................................................................................... 74
5.9. LED Indicator ......................................................................................................................... 75
5.9.1. Status LED ............................................................................................................................. 75
5.9.2. Port LED ................................................................................................................................. 76
5.9.3. Management Port LED .......................................................................................................... 78
5.10. Button ................................................................................................................................... 79
5.11. Thermal system ..................................................................................................................... 79
5.11.1. Temperature sensor .............................................................................................................. 79
5.11.2. Fan controller system ............................................................................................................ 81
5.12. CPLD ...................................................................................................................................... 83
5.12.1. CPLD1 pin-out list .................................................................................................................. 86
5.12.2. CPLD 1 Register ..................................................................................................................... 92
5.12.3. CPLD2 pin-out list ................................................................................................................ 108
5.12.4. CPLD 2 Register ................................................................................................................... 116
5.12.5. CPLD3 pin-out list ................................................................................................................ 141
5.12.6. CPLD 3 Register ................................................................................................................... 146
5.12.7. Fan CPLD pin-out list ........................................................................................................... 166
5.12.8. Fan board Register .............................................................................................................. 168
5.12.9. CPLD Field upgrade information ......................................................................................... 176
5.13. IDT 8V89307 ........................................................................................................................ 177
5.13.1. Configurations of IDT 8V89307 ........................................................................................... 177