gs110tpp

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
gs110tpp [2024/04/18 17:53] – Add JTAG tag svanheulegs110tpp [2025/01/28 06:44] (current) – Update LEDs and GPIOs svanheule
Line 20: Line 20:
 Communication with the Poe-CPU happens via a serial port, connected to the main CPU's UART1. Optocouplers are used to isolate the two circuits from each other and the communication frames can be sniffed from J3 (3.3V, 19200 baud, 8n1). Communication with the Poe-CPU happens via a serial port, connected to the main CPU's UART1. Optocouplers are used to isolate the two circuits from each other and the communication frames can be sniffed from J3 (3.3V, 19200 baud, 8n1).
  
-To indicate the global device status, two LEDs are present on the front panel. One is labelled 'PoE Max', and is likely controlled directly by the PoE MCU. +To indicate the global device status, two LEDs are present on the front panel. One is labelled 'PoE Max', and is controlled directly by the PoE MCU. 
-The other is labeled 'Power', and is used to indicate the device status. This LED appears to be an RGB LED, although it is currently unclear how the three colours are controlled.+The other is labeled 'Power', and is used to indicate the device status. This LED a three-component RGB LED, driven by thre individual GPIO lines of the RTL8231.
 All ports have a two-pin bi-color LED, used to indicate the link status: green for 1000M, orange for 100M. These are driven by three SN74HC164 shift registers, using 20 of the 24 outputs available. All ports have a two-pin bi-color LED, used to indicate the link status: green for 1000M, orange for 100M. These are driven by three SN74HC164 shift registers, using 20 of the 24 outputs available.
 PoE status bi-color LEDs are also available, with green used to indicate the remote device is PoE powered, and orange to signal a PoE fault status. The PoE-status LEDs are driven by two SN74LV595A shift registers, also controlled by the PoE MCU. PoE status bi-color LEDs are also available, with green used to indicate the remote device is PoE powered, and orange to signal a PoE fault status. The PoE-status LEDs are driven by two SN74LV595A shift registers, also controlled by the PoE MCU.
  
-There is also a SN74LVC125A four-port tri-state buffer whose purpose is currently unknown.+A SN74LVC125A four-port tri-state buffer is used to for the reset signal fan-out, driven by internal GPIO13 (TP7). 
 ==== Board pictures ==== ==== Board pictures ====
  
Line 36: Line 37:
     * GPIO2: connected to clock line of RTL8231. Output, used by MDIO/SMI peripheral (or bit-banged MDIO)     * GPIO2: connected to clock line of RTL8231. Output, used by MDIO/SMI peripheral (or bit-banged MDIO)
     * GPIO3: connected to data line of RTL8231. Input/output, used by MDIO/SMI peripheral (or bit-banged MDIO)     * GPIO3: connected to data line of RTL8231. Input/output, used by MDIO/SMI peripheral (or bit-banged MDIO)
-    * GPIO13: connected to #RESET pin of SoC (114). Output, active low, external pull-up.+    * GPIO13: connected to #RESET pin of SoC (114). Output, active low, external pull-up. Also resets the RTL8214C phy and the LED shift registers via the SN74LVC125A four-port buffer.
   * RTL8231 GPIO connections:   * RTL8231 GPIO connections:
 +    * GPIO10: PoE enable line, active high.
     * GPIO31, GPIO32, GPIO34: red, green, and blue components of the "Power" RGB LED. Output, active low.     * GPIO31, GPIO32, GPIO34: red, green, and blue components of the "Power" RGB LED. Output, active low.
   * Port LED:   * Port LED:
  • gs110tpp.txt
  • Last modified: 2025/01/28 06:44
  • by svanheule