zyxel_gs1920_series

This is an old revision of the document!


Zyxel GS1920 series

The GS1920 series is a line of managed gigabit ethernet switches. Two revisions exist, but both are built with Realtek hardware.

Switch name RJ45 ports Combo SFP ports Dedicated SFP ports PoE ports SoC
GS1920-24 28 4 - - RTL8392M
GS1920-24HP 28 4 - 24 RTL8392M
GS1920-48 48 4 2 - RTL8393M
GS1920-48HP 48 4 2 48 RTL8393M
GS1920-8HPv2 10 2 - 8 RTL8391M
GS1920-24v2 28 4 - - RTL8391M
GS1920-24HPv2 28 4 - 24 RTL8391M
GS1920-48v2 48 4 2 - RTL8393M
GS1920-48HPv2 48 4 2 48 RTL8393M

Hardware

  • SoC: RTL839x
  • Ethernet:
    • 3× RTL8218 (to be confirmed)
    • 1× RTL???? (combo ports)
  • RAM: Nanya NT5CB64M16FP-DH, 128MiB DDR3
  • Flash: Macronix MX25L1283F, 16MiB SPI NOR
  • PoE controller: STM32F100
  • PoE PSE: 6× BCM59111
  • GPIO:
    • RTL8231 as GPIO expander: I2C mode, device ID 0x3 (bus address 0x53), 8-bit register address width.
    • 3× RTL8231 as shift register: port status LEDs
    • HC164 shift register for device status LEDs
  • ADT7468 (I2C/SMBus) thermal controller with 3× 3-pin fan
  • Sipex SP3232 RS-232 transceiver

The serial port header J2 uses the standard DCE pinout, with TX/RX on pins 2 and 3, and ground on pin 5. Port settings are 9600 baud, 8n1, with ±5.6V logic levels.

The PoE management MCU and the ADT7468 fan controller are on a shared I2C bus. The PoE MCU is at address 0x20, while the fan controller is at (fixed) address 0x2E.

Photos

Board Pictures
Overview device front inside overview
Main board main board overview main board SoC and memory main board GPIOs main board fan control main board serial port and SFP cages main board backside
PoE daughter board PoE board PoE controller ICs PoE board backside
  • zyxel_gs1920_series.1609520051.txt.gz
  • Last modified: 2021/01/01 16:54
  • by svanheule