Superbrain - Backplane v1.0

This document shows the documentation for the Rhomb.io Backplane board.

Overview

The Backplane board is a certified Rhomb.io PCB that is used to connect several Neuron boards together to make up a complete computer cluster, to build a SuperBrain. Up to 8 Neuron boards can work together to get a high processing capacity. All of these boards can be replacing or adding without stopping or shutting down the system due to hot swap circuits.

The next figures show a 3D view for the Backplane board.

Backplane Top v1.png

Backplane Bottom v1.png

As a summary, the following table indicates the main features:

Backplane features
Ethernet 10BASE-T and 100BASE-TX

Applications:

  • SuperBrain computer cluster
  • Bitcoin mining

Board specifications

Key features

The Backplane board has been designed to use up to 8 Neuron boards to create an easier and more economical computer cluster due the flexibility of Rhomb.io technology. An ethernet switch, the KS8999, with eight 10/100 physical layer transceivers, is responsible for maintaining communication with the eight edge connectors of the board. All these connectors have a hot-swap circuit that allows to add or remove any Neuron without stopping or shutting down the system. The Backplane provides an standard MII (media-independent interface) to interface to external processors for router and gateway applications. The parts that make it possible are shown in the following block diagram.


Backplane Block Diagram v1.png


The following figures identify the main parts of the board. The most important parts will be explained with more details in the next sections.

Backplane Description Top.png

Backplane Description Bottom.png

Rhomb.io Core

The 'Backplane' board has no core sockets.


Rhomb.io Modules

The 'Backplane' board has no module sockets.

Memory

The 'Backplane' board has no memoty options.


Connectivity

Wired

There are available one Ethernet port that can carry traffic at the nominal rate of 100Mbit/s, supporting full and half-duplex with flow control.

Backplane Wired v1.png

Edge connectors

The Backplane board has eight edge connectors that allows to connect Neuron boards in order to work together. The following table shows the pinout of the edge connector.

Edge connector pinout
Bottom Top
Pin Pin name Description Pin Pin name Description
1 GND Connected to GND 2 VBP Backplane 12V
3 Hot plug Present-detect 4 VBP
5 Hot plug 6 VBP
7 GND Connected to GND 8 VBP
9 LED error Hot swap error indicator 10 ETH1_BDD2_N Ethernet 1 port
11 GND Connected to GND 12 ETH1_BDD2_P
13 USB2_HOST_N USB 2.0 port 14 GND Connected to GND
15 USB2_HOST_P 16 ETH1_RX_N Ethernet 1 port
17 GND Connected to GND 18 ETH1_BDD1_N
19 GPIO30 GPIO port 20 GND Connected to GND
21 GPIO29 22 ETH1_BDD1_P Ethernet 1 port
23 GPIO28 24 ETH1_RX_P
25 GPIO27 26 GND Connected to GND
27 GPIO26 28 ETH1_TX_N Ethernet 1 port
29 GPIO25 30 ETH_TX_P
31 GPIO24 32 ETH_CT
33 GPIO23 34 GND Connected to GND
35 GND Connected to GND 36 ETH2_BDD2_N Ethernet 2 port
37 PCIE_CLK_N PCIe port 38 ETH2_BDD2_P
39 PCIE_CLK_P 40 GND Connected to GND
41 PCIE_TX_N 42 ETH2_RX_N Ethernet 2 port
43 PCIE_TX_P 44 ETH2_BDD1_N
45 PCIE_RX_N 46 GND Connected to GND
47 PCIE_RX_P 48 ETH2_BDD1_P Ethernet 2 port
49 PCIE_WAKE 50 ETH2_RX_P
51 GND Conected to GND 52 GND Connected to GND
53 XEINT13 Interrupt port, CEC_HDMI 54 ETH2_TX_N Ethernet 2 port
55 XEINT07 Interrupt port, HPD_HDMI 56 ETH2_TX_P
57 XEINT05 Interrupt port 58 ETH2_CT
59 XEINT04 60 GND Connected to GND
61 PWM_OUT3 PWM 3 out 62 ETH3_BDD2_N Ethernet 3 port
63 PWM_OUT2 PWM 2 out 64 ETH3_BDD2_P
65 GND Connected to GND 66 GND Connected to GND
67 HDMI_D2_P HDMI Data 68 ETH3_RX_N Ethernet 3 port
69 HDMI_D2_N 70 ETH3_BDD1_N
71 HDMI_D1_P 72 GND Connected to GND
73 HDMI_D1_N 74 ETH3_BDD1_P Ethernet 3 port
75 HDMI_D0_P 76 ETH3_RX_P
77 HDMI_D0_N 78 GND Connected to GND
79 HDMI_CLK_P 80 ETH3_TX_N Ethernet 3 port
81 HDMI_CLK_N 82 ETH3_TX_P
83 GND Connected to GND 84 ETH3_CT
85 I2C1_SCL I2C 1 interface 86 GND Connected to GND
87 I2C1_SDA 88 ETH4_BDD2_N Ethernet 4 port
89 GND Connected to GND 90 ETH4_BDD"_P
91 UART3_TXD UART 3 interface 92 GND Connected to GND
93 UART3_RXD 94 ETH4_RX_N Ethernet 4 port
95 GND Connected to GND 96 ETH4_BDD1_N
97 UART2_TXD UART 2 interface 98 GND Connected to GND
99 UART2_RXD 100 ETH4_BDD1_P Ethernet 4 port
101 GND Connected to GND 102 ETH4_RX_P
103 UART1_CTSN UART 1 interface 104 GND Connected to GND
105 UART1_TXD 106 ETH4_TX_N Ethernet 4 port
107 UART1_RXD 108 ETH4_TX_P
109 UART1_RTSN 110 ETH4_CT
111 GND Connected to GND 112 GND Connected to GND
113 RFU Reserved 114 RFU Reserved
115 RFU 116 RFU
117 RFU 118 RFU
119 GND Connected to GND 120 GND Connected to GND

Wireless

The Backplane board has no wireless interfaces.


Video/Audio

The Backplane board has no audio and video interface.


LEDs and Button

4 LEDs are assembled on the Backplane board in order to give status feedback to the user. The functionality is explained next:

  • LED 36 shines when the 3V3 power supply source on the board is working.
  • LED 37 shines when the 2V5 power supply source on the board is working.
  • LED 38 shines when the 2V power supply source on the board is working.
  • LED 39 shines when the 1V1 power supply source on the board is working.

2 buttons are assembled on the Backplane board in order to reset the integrated circuits.

  • SW1 is used to reset the ethernet PHY
  • SW2 is used to reset the KS8999 switch

There are two pads to solde the wires of a panel mount switch.

Backplane LEDsandButton v1.png

Configuration Jumpers

The Backplane board has 39 solder jumpers that allow you to configure differents parameters of the KS8999 ethernet switch. When a solder jumper is bridged, the corresponding net is grounded and the integrate circuit modifies it configuration. The functionality of each one of them is explained on the following table:

Jumper Net Description
SJ1 MRXD0
SJ2 MRXD1 Port 9: D = Flow control
Port 9: U = No flow control
SJ3 MRXD2 Port 9: D = Half duplex
Port 9: U = Full duplex
SJ4 MRXD3 Port 9: D = 10 Mbps
Port 9: U = 100 Mbps
SJ5 LED1_0 Port 4: D = Disable auto-negotiation
SJ6 LED1_1 Port 3: D = Disable auto-negotiation
SJ7 LED1_2 Port 2: D = Disable auto-negotiation
SJ8 LED1_3 Port 1: D = Disable auto-negotiation
SJ9 LED2_0 Port 0: D = Disable auto-negotiation
SJ10 LED2_1 Port 1: D = Disable auto-negotiation
SJ11 LED2_2 Port 2: D = Disable auto-negotiation
SJ12 LED2_3 Port 3: D = Disable auto-negotiation
SJ13 LED3_0 Port 4: D = 10 Mbps
Port 4: F/U = 100 Mbps
SJ14 LED3_1 Port 3: D = 10 Mbps
Port 3: F/U = 100 Mbps
SJ15 LED3_2 Port 2: D = 10 Mbps
Port 2: F/U = 100 Mbps
SJ16 LED3_3 Port 1: D = 10 Mbps
Port 1: F/U = 100 Mbps
SJ17 LED4_0 Port 8: D = 10 Mbps
Port 8: F/U = 100 Mbps
SJ18 LED4_1 Port 7: D = 10 Mbps
Port 7: F/U = 100 Mbps
SJ19 LED4_2 Port 6: D = 10 Mbps
Port 6: F/U = 100 Mbps
SJ20 LED4_3 Port 5: D = 10 Mbps
Port 5: F/U = 100 Mbps
SJ21 LED6_0
SJ22 LED6_1
SJ23 LED6_3 D = Less agressive back-off
F/U = More agressive
SJ24 LED7_2 D = 5% broadcast frames allowed
F/U = Unlimited broadcast frames
SJ25 LED7_3 D = No flow control
F/U = Flow control enabled
SJ26 LED8_0 D = No half duplex back pressure
F/U = Hal duplex back pressure enabled
SJ27 LED8_1
SJ28 LED8_2 D = Max VLAN 1522 bytes, W/O VLAN 1518
F/U = 1536 bytes
SJ29 LED8_3 D = Asing disabled
F/U = Enable 5 minutes aging
SJ30 EN1P D =
F/U =
SJ31 PRSV D = No priority reserve
F/U = Reserve 6 KB for priority traffic
SJ32 CFGMODE D = CPU interface
F/U = EEPROM interface
SJ33 CLKMODE
SJ34 BIST
SJ35 SWM
SJ36 MODESEL0
SJ37 MODESEL1

D = pull-down; U = Pull-up; F = Float

SJ38 (MIIS1) SJ39 (MIIS0) Description
0 0 Disable MII
0 1 Reverse MII
1 0 Foward MII
1 1 7 wire mode (SNI)

Connections

Power

The Backplane board has two pads where you can solde the wires of a panel mount DC barrel connector. These pads are located under the switch pads. The input voltaje is 12V.

Secondary signals

The Neuron board doesn't use Analog to Digital, PWM and CLK signals.


Schematics

[This documentation is under construction. Please, be patient. We are working hard for bringing to you the best experience.]

Bill of materials

[This documentation is under construction. Please, be patient. We are working hard for bringing to you the best experience.]

Gerber files

[This documentation is under construction. Please, be patient. We are working hard for bringing to you the best experience.]

Part number package marking

Mechanical specifications

Board

Backplane Dimensions v1.png

Warranty

  • Precaution against Electrostatic Discharge. When handling Rhomb.io products, ensure that the environment is protected against static electricity. Follow the next recommendations:
  1. The users should wear anti-static clothing and use earth band when manipulating the device.
  2. All objects that come in direct contact with devices should be made of materials that do not produce static electricity that would cause damage.
  3. Equipment and work table must be earthed.
  4. Ionizer is recommended to remove electron charge.
  • Contamination. Be sure to use semiconductor products in the environment that may not be exposed to dust or dirt adhesion.
  • Temperature/Humidity. Semiconductor devices are sensitive to environment temperature and humidity. High temperature or humidity may deteriorate semiconductor devices characteristics. Therefore avoid storage or usage in such conditions.
  • Mechanical Shock. Care should be exercised not to apply excessive mechanical shock or force on the connectors and semiconductors devices.
  • Chemical. Do not expose semiconductor device to chemical because reaction to chemical may cause deterioration of device characteristics.
  • Light Protection. In case of non-EMC (Epoxy Molding Compound) package, do not expose semiconductor IC to strong light. It may cause devices malfunction. Some special products which utilize the light or have security function are excepted from this specification.
  • Radioactive, Cosmic and X-ray. Semiconductor devices can be influenced by radioactive, cosmic ray or X-ray. Radioactive, cosmic and X-ray may cause soft error during device operation. Therefore semiconductor devices must be shielded under environment that may be exposed to radioactive, cosmic ray or X-ray.
  • EMS (Electromagnetic Susceptibility). Note that semiconductor devices characteristics may be affected by strong electromagnetic waves or magnetic field during operation.


Disclaimer

Rhomb.io reserves the right to make corrections, enhancements, improvements and other changes to its products and services, and to discontinue any product or service. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All the hardware products are sold subject to the Rhomb.io terms and conditions of sale supplied at the time of order acknowledgment.

All brand names, trademarks and registered trademarks belong to their respective owners.

We are constantly striving to improve the quality of our technical notes. If you find an error or omission please let us know.

Email us at: info@rhomb.io