Microchip Technology VSC8211 User manual

 2022 Microchip Technology Inc. and its subsidiaries DS00004531A-page 1
1.0 INTRODUCTION
This document provides a hardware design checklist for the Microchip VSC8211 product family. It is meant to help cus-
tomers achieve first-pass design success. These checklist items should be followed when utilizing the VSC8211 in a
new design. A summary of these items is provided in Section 11.0, "Hardware Checklist Summary". Detailed information
on these subjects can be found in the corresponding sections:
•Section 2.0, "General Considerations"
•Section 3.0, "Power"
•Section 4.0, "Twisted Pair Media Interface (CAT5)"
•Section 5.0, "SGMII/SerDes MAC Interface"
•Section 6.0, "Parallel MAC Interface"
•Section 7.0, "Device Clocks"
•Section 8.0, "Hardware Configuration Using CMODE Pins"
•Section 9.0, "Digital Interface"
•Section 10.0, "Miscellaneous"
2.0 GENERAL CONSIDERATIONS
2.1 Required References
The VSC8211 implementor should have the following documents on hand:
•VSC8211 Single-Port 10/100/1000BASE-T, 1000BASE-X, and 100BASE-FX PHY Data Sheet
• Device documents on the VSC8211 product page at www.microchip.com
• VSC8211EV EVB schematics and PCB information in the VSC8211 Evaluation Board User Guide as well as
VSC8211 PCB design and layout guidelines at www.microchip.com.
2.2 Pin Check
• Check the pinout of the part against the data sheet. Ensure that all pins match the data sheet and are configured
as inputs, outputs, or bidirectional for error checking.
2.3 Ground
• A single ground reference as a system ground is used for all ground pins. Use one continuous ground plane to
ensure a low-impedance ground path and a continuous ground reference for all signals.
• A chassis ground is necessary between the magnetics and RJ45 connector at line side for better EMI and ESD.
VSC8211
Hardware Design Checklist

VSC8211
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3.0 POWER
Table 3-1 shows the power supply pins for the VSC8211.
TABLE 3-1: POWER SUPPLY PINS
Pin Name 117 LBGA
Ball
Voltage
(V) Descriptions Associated Functional Pins
Digital I/O Power Pins
VDDIOMAC C6, C3, D3 3.3V or
2.5V
Power for the parallel
MAC interface
RXLOS/SIGDET, RXD7:0], RXDV, RXER,
RXCLK, COL, CRS, TXCLK, TXER, GTX-
CLK, TXEN, TXD [7:0], MODDEF0/CLK-
OUTMAC
VDDIOMICRO G7 3.3V or
2.5V
3.3V or 2.5V,
Power for SMI,
EEPROM interface and
CLKOUTMICRO clock
EECLK/PLLMODE, EEDAT, TXDIS/,
SRESET, MDINT, MODDEF1/MDC, MODD-
EF2/MDIO, CLKOUTMICRO/OSCDIS
VDDIOCTRL D10 3.3V or
2.5V
Power for JTAG I/O RESET, TDO, TDI, TMS, TCK, TRST,
Digital Core Power Pins
VDD12 C10, C11, F3,
F4, G3
1.2V Power for internal digi-
tal logic, and SerDes/
SGMII I/O power
RDP, RDN, TDP, TDN, SCLKP, SCLKN,
SDIN, SDIP, SDOP, SDON
Analog Power Pins
VDD33A F10, G10, G9,
G8
3.3V Power for MDI,
CMODE, PLL, and LED
blocks. For analog core
power, use ferrite bead.
LED [4:0], CMODE7:0], TXVND, TXVPD,
TXVNC, TXVPC, TXVNB, TXVPB, TXVNA,
TXVPAXTAL2, XTAL1/REFCLK, REF-
FILT, REFREXT
VDD12A H7 1.2V Power of PLL and ADC
blocks. For analog core
power, use ferrite bead.
—
Ground Pins
VSS C5, D4, D5,
D6, D7, D8,
D9, E4, E5,
E6, E7, E8,
E9, E10, F5,
F6, F7, F8,
F9, J7, H9,
J9, H11, J11
0V Ground for all blocks —

 2022 Microchip Technology Inc. and its subsidiaries DS00004531A-page 3
VSC8211
3.1 Current and Power Requirements
• Ensure that the voltage regulators and power distribution are designed to adequately support these current
requirements for each power rail. Refer to Table 3-2 for different system configurations. Note that the power dissi-
pation values in the table need 25% to 30% based on the maximum current for the power supply designs of 3.3V,
1.2V, and 2.5V. Designs with 100Base-FX need an additional margin of 35% to 50% based on the typical current
for the power supply designs of 3.3V and 1.2V. See Table 3-3 for details.
TABLE 3-2: MAXIMUM RAIL CURRENT
Power Rail Voltage (V) Maximum Current (mA) Power Dissipation (mW)
VDDIO at 3.3V, RGMII-CAT5, 1000BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 110 363
VDDIOMAC, VDDIOMI-
CRO,
VDDIOCTRL
3.3 53 175
VDD12 1.2 324 389
VDD12A 1.2 38 46
VDDIO at 2.5V, RGMII-CAT5, 1000BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 110 363
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
2.5 41 103
VDD12 1.2 324 389
VDD12A 1.2 38 46
VDDIO at 3.3 V, RGMII-CAT5, 100BASE-TX, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 91.5 303
VDDIOMAC, VDDIOMI-
CRO,
VDDIOCTRL
3.3 19 63
VDD12 1.2 103 124
VDD12A 1.2 26.5 32
VDDIO at 2.5 V, RGMII-CAT5, 100BASE-TX, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 91.5 303
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
2.5 15 38
VDD12 1.2 103 124
VDD12A 1.2 26.5 32
VDDIO at 3.3 V, RGMII-CAT5, 10BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 152 502
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
3.3 14 46
VDD12 1.2 31 37
VDD12A 1.2 27 32
VDDIO at 2.5 V, RGMII-CAT5, 10BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 152 502
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
2.5 11 28

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VDD12 1.2 31 37
VDD12A 1.2 27 32
VDDIO at 3.3 V, RGMII-Fiber, 1000BASE-X, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 20 66
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
3.3 53 175
VDD12 1.2 56.5 68
VDD12A 1.2 23 28
VDDIO at 2.5 V, RGMII-Fiber, 1000BASE-X, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 20 66
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
2.5 42 105
VDD12 1.2 56.5 68
VDD12A 1.2 23 28
VDDIO at 3.3 V, SerDes-CAT5, 1000BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 112 370
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
3.3 14 46
VDD12 1.2 343 412
VDD12A 1.2 37 44
VDDIO at 2.5 V, SerDes-CAT5, 1000BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 112 370
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
2.5 10 33
VDD12 1.2 343 412
VDD12A 1.2 37 44
VDDIO at 3.3 V, SerDes-CAT5, 1000BASE-T, FD, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode On
VDD33A 3.3 112 370
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
3.3 14 46
VDD12 1.2 283 340
VDD12A 1.2 37 44
TABLE 3-2: MAXIMUM RAIL CURRENT
Power Rail Voltage (V) Maximum Current (mA) Power Dissipation (mW)

 2022 Microchip Technology Inc. and its subsidiaries DS00004531A-page 5
VSC8211
3.2 Power Supply Planes
• The VSC8211 requires two power rails of 3.3V and 1.2V or three power rails of VDDIO 2.5V, 3.3V, and 1.2V. The fil-
tered analog 1.2V and 3.3V supplies should not be shorted to any other digital supply at the package or PCB level.
See Section 3.3, "Power Circuit Connection and Analog Power Plane Filtering".
• The most important PCB design and layout considerations are as follows:
- Ensure that the return plane is adjacent to the power plane (without a signal layer in between).
- Ensure that a single plane is used for voltage reference with splits for individual voltage rails within that plane.
Try to maximize the area of each power split on the power plane based on corresponding via coordinates for
each rail to maximize coupling between each voltage rail and the return plane.
- Minimize resistive drop while efficiently conducting away heat from the device using 1 oz copper cladding.
• Four-layer PCBs with only one designated power plane must adhere to proper design techniques to prevent ran-
dom system events, such as CRC errors. Each power supply requires the lowest resistive drop possible to power
the pins of the device with correctly positioned local decoupling. For more information, see Section 3.4, "Bulk
Decoupling Capacitors".
• Ferrite beads should be used over a series inductor filter whenever possible, particularly for high-density or high-
power devices.
3.3 Power Circuit Connection and Analog Power Plane Filtering
• The analog power supplies are:
- VDD33A
- VDD12A
• A ferrite bead should be used to isolate each analog supply from the rest of the board. The bead should be placed
in series between the bulk decoupling capacitors and local decoupling capacitors.
• Because all PCB designs yield unique noise coupling behavior, not all ferrite beads or decoupling capacitors may
be needed for every design. It is recommended that system designers provide an option to replace the ferrite
beads with 0Ω resistors once a thorough evaluation of system performance is completed.
• Ferrite beads are not recommended for digital supplies VDDIOMAC, VDDIOMICRO, VDDIOCTRL, and VDD12.
The power and ground connections are shown in Figure 3-1.
TABLE 3-3: TYPICAL RAIL CURRENTS FOR DESIGN WITH 100BASE-FX
Power Rail Voltage (V) Typical Current (mA) Power Dissipation (mW)
VDDIO at 3.3V, RGMII-100BASE-FX, FDX, 1518 Byte Random Data Packet, 100% Utilization, SFP Mode Off
VDD33A 3.3 96 317
VDDIOMAC,
VDDIOMICRO,
VDDIOCTRL
3.3 19 63
VDD12 + VDD12A 1.2 145 174

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DS00004531A-page 6  2022 Microchip Technology Inc.and its subsidiaries
3.4 Bulk Decoupling Capacitors
• Bulk decoupling capacitors can be placed at any convenient position on the board. Local decoupling capacitors
should be X5R or X7R ceramic and placed as close as possible to the VSC8211's power pins.
• Make sure that enough bulk capacitors (1 µF to 22 µF) are incorporated in each power rail of the power supply.
• If the VSC8211 device is on the top layer of the printed circuit board (PCB), the best location for local decoupling
capacitors is on the bottom or underside of the PCB, directly under the device.
FIGURE 3-1: POWER SUPPLY CONNECTIONS AND LOCAL FILTERING
VSC8211
VDD33A
VSS
VDD12A
Ferrite
Bead
1.2V
0.1µF
1µF
10µF
Ferrite
Bead
3.3V
VDDMAC
4 pins
1µF 1µF
F10,G10,G9, G8 H7
C5, D4, D5, D6, D7,
D8, D9, E4, E5, E6,
E7, E8, E9, E10, F5,
F6, F7, F8, F9, J7,
H9, J9, H11, J11
VDD12
5 X 0.1µF
1.2V
5 pins
C10, C11,
F3, F4, G3
24 pins
4 X 0.1µF
3.3V or 2.5V
3 X 0.1µF
VDDIOMICRO
VDDIOCTRL
0.1µF
0.1µF
C6, C3, D3
G7
D10
1µF
3 pins

 2022 Microchip Technology Inc. and its subsidiaries DS00004531A-page 7
VSC8211
4.0 TWISTED PAIR MEDIA INTERFACE (CAT5)
4.1 10/100/1000 Mbps Interface Connection
The VSC8211 has one GPHY that supports 10/100/1000Base-T Ethernet Gigabit port. Details on the pin numbers for
this GPHY are described as follows:
•TXVNA (J12): This pin is the transmit/receive negative connection from Pair A of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVPA (J13): This pin is the transmit/receive positive connection from Pair A of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVNB (H12): This pin is the transmit/receive negative connection from Pair B of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVPB (H13): This pin is the transmit/receive positive connection from Pair B of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVNC (G12): This pin is the transmit/receive negative connection from Pair C of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVPC (G13): This pin is the transmit/receive positive connection from Pair C of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVND (F12): This pin is the transmit/receive negative connection from Pair D of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
•TXVPD (F13): This pin is the transmit/receive positive connection from Pair D of the internal GPHY. This pin con-
nects to the 10/100/1000 magnetics. No external terminator and bias are needed.
There are two types of 10/100/1000 Mbps channel connection solutions. As shown in Figure 4-1, the first solution is for
cases wherein no electrical noise external environment and ESD are taken into consideration. The second solution, on
the other hand, is for instances wherein electrical noise external environment and ESD are considered. See Figure 4-2.
FIGURE 4-1: FIRST SOLUTION FOR 10/100/1000 MBPS CHANNEL CONNECTION
VSC8211
TXVNA
4 x 0.1µF
RJ45
CONNECTOR
4 x 75Ω
System GND
8
7
6
5
4
2
1
J12
MAGNETICS
J13
H12
H13
G12
G13
F12
F13
Channel A
Channel B
Channel C
Channel D
TXVPA
Chassis GND
Metal Case
1000pF 2KV
3TXVNB
TXVPB
TXVNC
TXVPC
TXVND
TXVPD
RJ45
Chassis GND

VSC8211
DS00004531A-page 8  2022 Microchip Technology Inc.and its subsidiaries
4.2 10/100/1000 Magnetics and RJ45 Connector Connection
• The center tap connection on the VSC8211 side for Pair A channel only connects a 0.1 µF capacitor to GND. No
bias is needed.
• The center tap connection on the VSC8211 side for Pair B channel only connects a 0.1 µF capacitor to GND. No
bias is needed.
• The center tap connection on the VSC8211 side for Pair C channel only connects a 0.1 µF capacitor to GND. No
bias is needed.
• The center tap connection on the VSC8211 side for Pair D channel only connects a 0.1 µF capacitor to GND. No
bias is needed.
• The center taps from all four pairs of the magnetics should not be connected together without the 0.1 µF capaci-
tors to ground. The reason is the common-mode voltage can be different between pairs, especially for 10/100
operation. (Pairs A and B are active, while Pairs C and D are inactive.)
• It is recommended that the center tap connection for each pair (A, B, C, and D) on the cable side (RJ45 side) be
terminated with a 75Ω resistor through a common 1000 pF, 2 kV capacitor to chassis ground.
• Only one 1000 pF, 2 kV capacitor to chassis ground is required. It is shared by Pair A, Pair B, Pair C, and Pair D
center taps.
• Only one 1000 pF, 2 kV capacitor or a ferrite bead should connect between the chassis ground and the system
ground.
• The RJ45 shield should connect to the chassis ground. This includes RJ45 connectors with or without integrated
magnetics. See Section 4.3, "PCB Layout Considerations" for guidance on how the chassis ground should be cre-
ated from system ground.
• For the magnetics selection, please refer to magnetics suggested guidelines (ENT-AN0098 Magnetics Guide on
Microchip Technology product page) for reference.
FIGURE 4-2: SECOND SOLUTION FOR 10/100/1000 MBPS CHANNEL CONNECTION
1000pF 2KV
System GND Chassis GND
Ferrite bead
VSC8211
TXVNA
4 x 0.1µF
RJ45
CONNECTOR
4 x 75Ω
System GND
8
7
6
5
4
2
1
J12
MAGNETICS
J13
H12
H13
G12
G13
F12
F13
Channel A
Channel B
Channel C
Channel D
TXVPA
Chassis GND
Metal Case
1000pF 2KV
3TXVNB
TXVPB
TXVNC
TXVPC
TXVND
TXVPD
RJ45
Chassis GND

 2022 Microchip Technology Inc. and its subsidiaries DS00004531A-page 9
VSC8211
4.3 PCB Layout Considerations
• All differential pairs of the MDI interface traces should have a characteristic impedance of 100Ω to the GND plane.
This is a strict requirement to minimize return loss that requires a PCB designer and FAB house.
• Each MDI pair should be placed as close as possible in parallel to minimize EMI and crosstalk. Each member of a
pair should be matched in length to prevent mismatch in delay that would cause common-mode noise.
• Ideally, there should be no crossover or via on the signal paths.
• Incorporate a 1000 pF 2 kV capacitor or a ferrite bead to connect between the chassis ground and the system
ground. This allows some flexibility at EMI testing for different grounding options if leaving the footprint open
keeps the two grounds separated. For best performance, short the grounds together with a ferrite bead or a
capacitor. Users are required to place the capacitor or ferrite bead far away from the VSC8211 device or other
sensitive devices in the PCB layout placement for better ESD.
4.4 100 MBPS Fiber Support Over Copper Media Interface
• The VSC8211 supports 100BASE-FX over its copper media interface by using pairs A and B, which provide TX
and RX differential connections, respectively. If the fiber module does not have internal AC coupling capacitors,
then they are required between the PHY and fiber module. The value should be 0.1 µF.
• The RXLOS/SIGDET signal is not used in this mode.
• The PHY can be brought into the 100BASE-FX Operation mode using the following configuring sequence:
1. Initialize the PHY into the specific MAC-to-Copper Operating mode for the MAC interface type required
(register23).
2. Disable Auto-Negotiation and force the 100BASE-T FDX mode (register 0).
3. Run the 100BASE-FX initialization script. For more details, see Section 33.4 of the data sheet.
•Figure 4-3 shows the copper media interface connections to 100Base-FX SFP.
FIGURE 4-3: COPPER MEDIA INTERFACE CONNECTIONS FOR 100BASE-FX
100BASE-FX
SFP Modules
TD+
TD-
RD+
RD-
RX_LOS
SFP Module
TX_FAULT
MOD_DEF0
/PRESENT
RATE_SELECT
TX_DISABLE
MOD_DEF1/SCL
MOD_DEF2/SDA
VSC8211
Copper Media Interface
100 Ω
100 Ω
TXVPA
TXVNA
TXVPB
TXVNB H12
H13
J12
J13
Note:
 SFP module has AC coupling capacitors and termination resistors
internally for TD+/- pair and RD+/- pair.
 SFP MOD_DEF0 pin can connect to a LED. The LED can be turned on
to indicate SFP present when SFP module is plugged in, because this
MOD_DEF0 pin has an internal about 100Ω pull-down resistor.
3.3V

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DS00004531A-page 10  2022 Microchip Technology Inc.and its subsidiaries
5.0 SGMII/SERDES MAC INTERFACE
5.1 SGMII/SerDes MAC Pins and Connection
• The VSC8211 device supports one SGMII (Serial Gigabit Media Independent Interface) MAC or one SerDes
MACs.
• Refer to Table 5-1 for pin number details. For SGMII/SerDes interface connections, see Figure 5-1 and Figure 5-2.
5.2 SGMII/SerDes MAC
• SGMII (Serial Gigabit Media Independent Interface) serializes a gigabit interface (such as GMII) into a high-speed,
two-pin differential interface. Using SGMII/SerDes can reduce the pin count to four pins per Ethernet port.
TABLE 5-1: SGMII/SERDES MAC INTERFACE PINS
Pin Name Pin Number Type Description
RDN H1 Output DIFF Receiver Data Differential Output Pair (used in SerDes/SGMII to CAT5
and Parallel MAC to SerDes/AMS PHY operating modes)
RDP H2 Output DIFF
TDN J4 Input DIFF Transmitter Data Differential Input Pair (used in SerDes/SGMII to CAT5
and Parallel MAC to SerDes/AMS PHY operating modes)
TDP J3 Input DIFF
SCLKN J2 Output DIFF SGMII Clock Differential Output Pair (used in SGMII to CAT5/SerDes/
AMS PHY operating modes).
SCLKP J1 Output DIFF
SDIP G2 Input DIFF Fiber Transceiver Differential Input Pair (used in SGMII to SerDes)
SDIN G1 Input DIFF Fiber 1000Base-X SFP operation mode
SDOP F2 Output DIFF Fiber Transceiver Differential Output Pair (used in SGMII to SerDes)
SDON F1 Output DIFF Fiber 1000Base-X SFP operation mode
FIGURE 5-1: SGMII/SERDES MAC INTERFACE CONNECTIONS
VSC8211
SGMII/SerDes MAC Interface
SGMII/SerDes MAC
100 Ω
100 Ω
TDP
TDN
RDP
RDN
TDP
TDN
RDP
RDN
0.01µF
0.01µF
0.01µF
0.01µF
H1
H2
J4
J3
SGMII/SerDes Controller
SGMII/SerDes MAC side termination
depends on SGMII/SerDes MAC request
100 Ω
SCLKP
SCLKN
SCLKP
SCLKN
0.01µF
0.01µF
J2
J1
Optional- May not be
required by the MAC
3.3V
SIGDET
C7
4.7K Ω