Asus PRIME A520M-K User manual

Motherboard
PRIME A520M-K

ii
E16800
First Edition
June 2020
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iii
Contents
Safety information...................................................................................................... iv
About this guide.......................................................................................................... v
Package contents....................................................................................................... vi
PRIME A520M-K specifications summary................................................................ vi
Chapter 1 Product Introduction
1.1 Before you proceed...................................................................................... 1-1
1.2 Motherboard overview .................................................................................1-1
1.3 Central Processing Unit (CPU).................................................................... 1-7
1.4 System memory............................................................................................ 1-8
Chapter 2 BIOS and RAID Support
2.1 Knowing BIOS...............................................................................................2-1
2.2 BIOS Setup program ....................................................................................2-2
2.3 ASUS EZ Flash 3...........................................................................................2-3
2.4 ASUS CrashFree BIOS 3.............................................................................. 2-4
2.5 RAID configurations..................................................................................... 2-5
Appendix
Notices ..................................................................................................................... A-1
ASUS contact information...................................................................................... A-6

iv
Safety information
Electrical safety
• To prevent electrical shock hazard, disconnect the power cable from the electrical outlet
before relocating the system.
• When adding or removing devices to or from the system, ensure that the power cables
for the devices are unplugged before the signal cables are connected. If possible,
disconnect all power cables from the existing system before you add a device.
• Before connecting or removing signal cables from the motherboard, ensure that all power
cables are unplugged.
• Seek professional assistance before using an adapter or extension cord. These devices
could interrupt the grounding circuit.
• Ensure that your power supply is set to the correct voltage in your area. If you are not
sure about the voltage of the electrical outlet you are using, contact your local power
company.
• If the power supply is broken, do not try to x it by yourself. Contact a qualied service
technician or your retailer.
Operation safety
• Before installing the motherboard and adding components, carefully read all the manuals
that came with the package.
• Before using the product, ensure all cables are correctly connected and the power cables
are not damaged. If you detect any damage, contact your dealer immediately.
• To avoid short circuits, keep paper clips, screws, and staples away from connectors,
slots, sockets and circuitry.
• Avoid dust, humidity, and temperature extremes. Do not place the product in any area
where it may be exposed to moisture.
• Place the product on a stable surface.
• If you encounter technical problems with the product, contact a qualied service
technician or your retailer.
• Your motherboard should only be used in environments with ambient temperatures
between 0°C and 40°C.

v
About this guide
This user guide contains the information you need when installing and conguring the
motherboard.
How this guide is organized
This guide contains the following parts:
• Chapter 1: Product Introduction
This chapter describes the features of the motherboard and the new technology it
supports. It includes descriptions of the switches, jumpers, and connectors on the
motherboard.
• Chapter 2: BIOS and RAID Support
This chapter tells how to boot into the BIOS, upgrade BIOS using the EZ Flash Utility
and support on RAID.
Where to find more information
Refer to the following sources for additional information and for product and software
updates.
1. ASUS website
The ASUS website provides updated information on ASUS hardware and software
products. Refer to the ASUS contact information.
2. Optional documentation
Your product package may include optional documentation, such as warranty flyers,
that may have been added by your dealer. These documents are not part of the
standard package.
Conventions used in this guide
To ensure that you perform certain tasks properly, take note of the following symbols used
throughout this manual.
CAUTION: Information to prevent damage to the components and injuries to
yourself when trying to complete a task.
IMPORTANT: Instructions that you MUST follow to complete a task.
NOTE: Tips and additional information to help you complete a task.

vi
PRIME A520M-K specifications summary
CPU
AMD Socket AM4 for 3rd Gen AMD Ryzen™ and 3rd Gen AMD Ryzen™
with Radeon™ Graphics Processors*
*Refer to www.asus.com for CPU support list.
Chipset AMD A520 Chipset
Memory
2 x DIMM, Max. 64GB, DDR4 4600(O.C.)/4400(O.C.)/4000(O
.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3333(O
.C.)/3200/3000/2800/2666/2400/2133 MHz, Un-buffered Memory*
Dual Channel Memory Architecture
*ECC Memory (ECC mode) support varies by CPU.
**Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists).
Graphics 1 x D-Sub
1 x HDMITM 2.1(4K@60HZ)
Expansion Slots
3rd Gen AMD Ryzen™ and 3rd Gen AMD Ryzen™ with Radeon™
Graphics Processors
1 x PCIe 3.0 x16 slot (supports x16 mode)
AMD A520 Chipset
2 x PCIe 3.0 x1 slots
Storage
Total supports 1 x M.2 slot and 4 x SATA 6Gb/s ports
3rd Gen AMD Ryzen™ and 3rd Gen AMD Ryzen™ with Radeon™
Graphics Processors
M.2 slot (Key M), type 2242/2260/2280 (supports PCIe 3.0 x4 & SATA
modes)
AMD A520 Chipset
4 x SATA 6Gb/s ports
Support RAID 0, 1, 10
Ethernet 1 x Realtek RTL8111H 1Gb Ethernet
USB
Rear USB (Total 6 ports)
4 x USB 3.2 Gen 1 ports (4 x Type-A)
2 x USB 2.0 ports (2 x Type-A)
Front USB (Total 6 ports)
1 x USB 3.2 Gen 1 header supports additional 2 USB 3.2 Gen 1 ports
2 x USB 2.0 headers support additional 4 USB 2.0 ports
(continued on the next page)
Package contents
Check your motherboard package for the following items.
Motherboard 1 x PRIME A520M-K motherboard
Cables 2 x SATA 6Gb/s cables
Miscellaneous 1 x I/O Shield
1 x M.2 SSD screw package
Application DVD 1 x Support DVD
Documentation 1 x User manual
If any of the above items is damaged or missing, contact your retailer.

vii
PRIME A520M-K specifications summary
Audio
Realtek ALC887 7.1 Surround Sound High Definition Audio CODEC*
- Supports Jack detection, Multi-streaming, Front Panel Jack-retasking
- Supports up to 24-Bit/192 kHz playback
Audio Features
- Audio Shielding
- Dedicated audio PCB layers
*A chassis with an HD audio module in the front panel is required to support 7.1
Surround Sound audio output.
Back Panel I/O Ports
4 x USB 3.2 Gen 1 ports (4 x Type-A)
2 x USB 2.0 ports (2 x Type-A)
1 x D-Sub port
1 x HDMITM port
1 x Realtek RTL8111H 1Gb Ethernet port
3 x Audio jacks
1 x PS/2 Keyboard/Mouse combo port
Internal I/O
Connectors
Fan and cooling related
1 x 4-pin CPU Fan header
1 x 4-pin Chassis Fan header
Power related
1 x 24-pin Main Power connector
1 x 8-pin +12V Power connector
Storage related
1 x M.2 slot (Key M)
4 x SATA 6Gb/s ports
USB
1 x USB 3.2 Gen 1 header supports additional 2 USB 3.2 Gen 1 ports
2 x USB 2.0 headers support additional 4 USB 2.0 ports
Miscellaneous
1 x Clear CMOS header
1 x COM Port header
1 x Front Panel Audio header (AAFP)
1 x S/PDIF Out header
1 x Speaker header
1 x SPI TPM header (14-1pin)
1 x 10-1 pin System Panel header
(continued on the next page)

viii
PRIME A520M-K specifications summary
Special Features
ASUS 5X PROTECTION III
- ASUS DIGI+ VRM
- ASUS LANGuard
- ASUS Overvoltage Protection
- ASUS SafeSlot Core
- ASUS Stainless-Steel Back I/O
ASUS Q-Design
- ASUS Q-DIMM
- ASUS Q-Slot
ASUS Thermal Solution
- Aluminum heatsink design
Software Features
ASUS Exclusive Software
Armoury Crate
AI Suite 3
- Performance and Power Saving Utility
TurboV EVO
EPU
DIGI+ VRM
Fan Xpert
- EZ update
ASUS CPU-Z
AI Charger
DAEMON Tools
Norton Anti-virus software (Free Trial for 60 days)
WinRAR
UEFI BIOS
ASUS EZ DIY
- ASUS CrashFree BIOS 3
- ASUS EZ Flash 3
- ASUS UEFI BIOS EZ Mode
BIOS 256 Mb Flash ROM, UEFI AMI BIOS
Manageability WOL by PME, PXE
Operating System Windows 10 - 64 bit
Form Factor mATX Form Factor
8.9 inch x 8.7 inch (22.6 cm x 22.1 cm)
Specications are subject to change without notice. Refer to the ASUS website for the
latest specications.

ASUS PRIME A520M-K 1-1
Product Introduction
1
1.1 Before you proceed
Take note of the following precautions before you install motherboard components or change
any motherboard settings.
• Unplug the power cord from the wall socket before touching any component.
• Before handling components, use a grounded wrist strap or touch a safely grounded
object or a metal object, such as the power supply case, to avoid damaging them due
to static electricity.
• Before you install or remove any component, ensure that the ATX power supply is
switched off or the power cord is detached from the power supply. Failure to do so
may cause severe damage to the motherboard, peripherals, or components.
Unplug the power cord before installing or removing the motherboard. Failure to do so can
cause you physical injury and damage motherboard components.
1.2 Motherboard overview
Place this
side towards
the rear of the
chassis
DDR4 DIMM_A1* (64bit, 288-pin module) DDR4 DIMM_B1* (64bit, 288-pin module)
DIGI+
VRM
CPU_FAN
COM_DEBUG
CHA_FAN TPM
F_PANEL
AAFP
SPDIF_OUT
CLRTC
SATA6G_2SATA6G_1
SATA6G_3 SATA6G_4
256Mb
BIOS
EATX12V
EATXPWR
U32G1_12
AMD
A520
BATTERY
USB56
LAN_U32G1_34
KBMS
_U32G1_56
VGA
HDMI
AUDIO
Super
I/O
PCIEX1_1
PCIEX1_2
M.2(SOCKET3)
2280 2260 2242
PCIEX16
USB34USB12
COM
22.1cm(8.7in)
22.6cm(8.9in)
SOCKET AM4
ALC
887
Realtek
8111H
SPEAKER
8
5
13 1112 10
3
5 1 24 4
7169
6
15
14

1-2 Chapter 1: Product Introduction
1.2.1 Layout contents
1. CPU socket
The motherboard comes with an AMD Socket AM4 designed for 3rd Gen AMD Ryzen™ and
3rd Gen AMD Ryzen™ with Radeon™ Graphics Processors.
For more details, refer to Central Processing Unit (CPU).
2. DDR4 DIMM slots
The motherboard comes with Dual Inline Memory Modules (DIMM) slots designed for DDR4
(Double Data Rate 4) memory modules.
For more details, refer to System memory.
3. Expansion slots
This motherboard supports one PCIe x16 graphics card and two PCIe 3.0 x1 network cards,
SCSI cards and other cards that comply with the PCI Express specication.
4. Fan headers
The Fan headers allow you to connect fans to cool the system.
5. Power connectors
These Power connectors allow you to connect your motherboard to a power supply. The
power supply plugs are designed to t in only one orientation. Find the proper orientation and
push down rmly until the power supply plugs are fully inserted.
Ensure to connect the 8-pin power plug.
• For a fully congured system, we recommend that you use a power supply unit
(PSU) that complies with ATX 12V Specication 2.0 (or later version) and provides a
minimum power of 350W.
• We recommend that you use a PSU with a higher power output when conguring a
system with more power-consuming devices. The system may become unstable or
may not boot up if the power is inadequate.
• If you are uncertain about the minimum power supply requirement for your system, we
recommend you to refer to online resources for Power Supply Wattage Calculator.
6. M.2 Slot (Key M)
The M.2 slot allows you to install an M.2 device such as an M.2 SSD module.
For 3rd Gen AMD Ryzen™ and 3rd Gen AMD Ryzen™ with Radeon™ Graphics Processors,
M.2 slot supports PCIe 3.0 x4 & SATA mode Key M and type 2242/2260/2280 storage
devices.
7. SATA 6Gb/s ports
The SATA 6Gb/s ports allow you to connect SATA devices such as optical disc drives and
hard disk drives via a SATA cable.
GND FAN PWR FAN IN FAN PWM
FAN PWM
FAN IN
FAN PWR
GND

ASUS PRIME A520M-K 1-3
8. USB 3.2 Gen 1 header
The USB 3.2 Gen 1 header allows you to connect a USB 3.2 Gen 1
module for additional USB 3.2 Gen 1 ports. The USB 3.2 Gen 1 header
provides data transfer speeds of up to 5 Gb/s.
The USB 3.2 Gen 1 module is purchased separately.
9. USB 2.0 headers
The USB 2.0 headers allow you to connect USB modules for additional USB
2.0 ports. The USB 2.0 headers provide data transfer speeds of up to 480
Mb/s.
DO NOT connect a 1394 cable to the USB connectors. Doing so will
damage the motherboard!
The USB 2.0 module is purchased separately.
10. Clear CMOS header
This header allows you to clear the CMOS RTC RAM data of the system setup
information such as date, time, and system passwords.
To erase the RTC RAM:
1. Turn OFF the computer and unplug the power cord.
2. Use a metal object such as a screwdriver to short the two pins.
3. Plug the power cord and turn ON the computer.
4. Hold down the <Del> key during the boot process and enter BIOS setup to re-
enter data.
If the steps above do not help, remove the onboard battery and short the two pins again to
clear the CMOS RTC RAM data. After clearing the CMOS, reinstall the battery.
11. COM Port header
This header is for a serial (COM) port. Connect the serial port module cable to
this header, then install the module to a slot opening at the back of the system
chassis.
12. Front Panel Audio header
This header is for a chassis-mounted front panel audio I/O module that
supports HD audio standard. Connect one end of the front panel audio
I/O module cable to this header.
• We recommend that you connect a high-denition front panel
audio module to this header to avail of the motherboard’s high-
denition audio capability.
• If you want to connect a high-denition front panel audio
module to this header, set the Front Panel Type item in the
BIOS setup to [HD Audio]. By default, this header is set to [HD
Audio].
USB3+5V
IntA_P1_SSRX-
IntA_P1_SSRX+
GND
IntA_P1_SSTX-
IntA_P1_SSTX+
GND
IntA_P1_D-
IntA_P1_D+
GND
PIN 1
USB3+5V
IntA_P2_SSRX-
IntA_P2_SSRX+
GND
IntA_P2_SSTX-
IntA_P2_SSTX+
GND
IntA_P2_D-
IntA_P2_D+
CLRTC
+3V_BAT GND
PIN 1
PIN 1
COM
DCD
TXD
GND
RTS
RI
RXD
DTR
DSR
CTS
AAFP
AGND NC SENSE1_RETUR SENSE2_RETUR
PORT1 L
PORT1 R PORT2 R
SENSE_SEND
PORT2 L
HD-audio-compliant
pin definition
PIN 1
USB+5V USB_P1- USB_P1+ GND NC
USB+5V
USB_P2-
USB_P2+
GND

1-4 Chapter 1: Product Introduction
13. S/PDIF Out header
This header is for an additional Sony/Philips Digital Interface (S/PDIF) port.
Connect the S/PDIF Out module cable to this header, then install the module to
a slot opening at the back of the system chassis.
14. Speaker header
The 4-pin header is for the chassis-mounted system warning speaker. The
speaker allows you to hear system beeps and warnings.
15. SPI TPM header
This header supports a Trusted Platform Module (TPM) system with a Serial
Peripheral Interface (SPI), allowing you to securely store keys, digital
certicates, passwords, and data. A TPM system also helps enhance
network security, protects digital identities, and ensures platform integrity.
16. 10-1 pin System Panel header
This header supports several chassis-mounted functions.
• System power LED (2-pin +PWR_LED-)
This 2-pin header is for the system power LED. Connect the chassis
power LED cable to this header. The system power LED lights up when
you turn on the system power, and blinks when the system is in sleep
mode.
• Hard disk drive activity LED (2-pin +HDD_LED-)
This 2-pin header is for the HDD Activity LED. Connect the HDD Activity LED cable to
this header. The HDD LED lights up or flashes when data is read from or written to the
HDD.
• Power button/Soft-off button (2-pin PWR_BTN)
This header is for the system power button.
• Reset button (2-pin RESET)
This 2-pin header is for the chassis-mounted reset button for system reboot without
turning off the system power.
TPM
PIN 1
T_SPI_MOSI
T_SPI_CLK
GND
F_BIOS_WP#_R
S_SPI_TPM_CS2#
S_SPI_TPM_IRQ#
F_SPI_HOLD#_R T_SPI_MISO F_SPI_CS0#_R +3V_SPI F2_SPI_CS1#_R S_PLTRST# VCCSPI
PIN 1
PWR_BTN
PWR_LED+ PWR_LED- PWR GND
HDD_LED+
HDD_LED-
Ground
HWRST#
(NC)
F_PANEL
+PWR_LED-
+HDD_LED- RESET
SPDIF_OUT
+5V SPDIFOUT GND
+5V GND GND Speaker Out
SPEAKER
PIN 1

ASUS PRIME A520M-K 1-5
1.2.2 Rear panel connectors
Ethernet port
Speed
LED
Activity Link
LED
Activity/Link LED Speed LED
Status Description Status Description
Off No link Off 10Mbps connection
Orange Linked Orange 100Mbps connection
Orange (Blinking) Data activity Green 1Gbps connection
Orange (Blinking
then steady)
Ready to wake
up from S5 mode
1 2
6 7 8 6 9
3 4 5
Ethernet port LED indications
1. PS/2 Keyboard/Mouse combo port. This port is for a PS/2 keyboard or mouse.
2. Video Graphics Adapter (VGA) port. This 15-pin port is for a VGA monitor or other
VGA-compatible devices.
3. Ethernet port. This port allows Gigabit connection to a Local Area Network (LAN)
through a network hub. Refer to the table below for the Ethernet port LED indications.
4. Line In port (light blue). This port connects the tape, CD, DVD player, or other audio
sources.
5. Line Out port (lime). This port connects a headphone or a speaker. In 4-channel,
5.1-channel, and 7.1-channel congurations, the function of this port becomes Front
Speaker Out.
6. USB 3.2 Gen 1 (up to 5Gbps) ports. These 9-pin Universal Serial Bus (USB) ports
connect to USB 3.2 Gen 1 devices.
7. HDMITM port. This port is for a High-Denition Multimedia Interface (HDMITM)
connector, and is HDCP compliant allowing playback of HD DVD, Blu-ray, and other
protected content.
8. USB 2.0 ports. These 4-pin Universal Serial Bus (USB) ports are for USB 2.0 devices.

1-6 Chapter 1: Product Introduction
9. Microphone port (pink). This port connects a microphone.
Refer to the audio conguration table for the function of the audio ports in 2, 4, 5.1, or
7.1-channel conguration.
Audio 2, 4, 5.1 or 7.1-channel configuration
Port Headset
2-channel 4-channel 5.1-channel 7.1-channel
Light Blue
(Rear panel) Line In Rear Speaker Out Rear Speaker Out Rear Speaker Out
Lime (Rear panel) Line Out Front Speaker Out Front Speaker Out Front Speaker Out
Pink (Rear panel) Mic In Mic In Bass/Center Bass/Center
Lime (Front panel) — — — Side Speaker Out
To configure a 7.1-channel audio output:
A chassis with an HD audio module in the front panel is required to support 7.1-channel
audio output.

ASUS PRIME A520M-K 1-7
1.3 Central Processing Unit (CPU)
The motherboard comes with an AMD Socket AM4 designed for
3rd Gen AMD Ryzen™ and 3rd Gen AMD Ryzen™ with Radeon™
Graphics Processors.
Unplug all power cables before installing the CPU.
Installing the CPU
Apply the Thermal Interface Material to the CPU heatsink and CPU before you install the
heatsink and fan if necessary.
1
3
2
4
The AM4 socket has a different pinout design. Ensure that you use a CPU designed for the
AM4 socket. The CPU ts in only one correct orientation. DO NOT force the CPU into the
socket to prevent bending the connectors on the socket and damaging the CPU!

1-8 Chapter 1: Product Introduction
1.4 System memory
This motherboard comes with two Double Data Rate 4 (DDR4) Dual Inline Memory Module
(DIMM) sockets. The gure illustrates the location of the DDR4 DIMM sockets:
• You may install varying memory sizes in Channel A and Channel B. The system
maps the total size of the lower-sized channel for the dual-channel conguration. Any
excess memory from the higher-sized channel is then mapped for single-channel
operation.
• Always install DIMMs with the same CAS latency. For optimal compatibility, we
recommend that you install memory modules of the same version or date code (D/C)
from the same vendor. Check with the retailer to get the correct memory modules.
• A DDR4 memory module is notched differently from a DDR, DDR2, or DDR3 module.
DO NOT install a DDR, DDR2, or DDR3 memory module to the DDR4 slot.
Recommended memory configuration
• The default memory operation frequency is dependent on its Serial Presence
Detect(SPD), which is the standard way of accessing information from a memory
module. Under the default state, some memory modules for overclocking may operate
at a lower frequency than the vendor-marked value.
• For system stability, use a more efcient memory cooling system to support a full
memory load (2 DIMMs).
• Refer to www.asus.com for the latest Memory QVL (Qualied Vendors Lists).
Channel Sockets
Channel A DIMM_A1*
Channel B DIMM_B1*
DIMM_B1*
DIMM_A1*
DIMM_A1*
DIMM_B1*
DIMM_B1* DIMM_A1*

ASUS PRIME A520M-K 1-9
Installing a DIMM
1 2
B
A
A
To remove a DIMM
B
A

1-10 Chapter 1: Product Introduction

ASUS PRIME A520M-K 2-1
BIOS and RAID Support
2
2.1 Knowing BIOS
The new ASUS UEFI BIOS is a Unied Extensible Interface that complies with UEFI
architecture, offering a user-friendly interface that goes beyond the traditional keyboard-
only BIOS controls to enable a more flexible and convenient mouse input. You can easily
navigate the new UEFI BIOS with the same smoothness as your operating system. The
term “BIOS” in this user manual refers to “UEFI BIOS” unless otherwise specied.
BIOS (Basic Input and Output System) stores system hardware settings such as storage
device conguration, overclocking settings, advanced power management, and boot
device conguration that are needed for system startup in the motherboard CMOS. In
normal circumstances, the default BIOS settings apply to most conditions to ensure
optimal performance. DO NOT change the default BIOS settings except in the following
circumstances:
• An error message appears on the screen during the system bootup and requests you
to run the BIOS Setup.
• You have installed a new system component that requires further BIOS settings or
update.
Inappropriate BIOS settings may result to instability or boot failure. We strongly
recommend that you change the BIOS settings only with the help of a trained service
personnel.
• When downloading or updating the BIOS le, rename it as PA520MK.CAP for this
motherboard.
• BIOS settings and options may vary due to different BIOS release versions. Please
refer to the latest BIOS version for settings and options.
For more information on BIOS congurations, please refer to
https://www.asus.com/support, or download the BIOS manual
by scanning the QR code.

2-2 Chapter 2: BIOS and RAID Support
2.2 BIOS Setup program
Use the BIOS Setup to update the BIOS or congure its parameters. The BIOS screens
include navigation keys and brief onscreen help to guide you in using the BIOS Setup
program.
Entering BIOS at startup
To enter BIOS Setup at startup, press <Delete> or <F2> during the Power-On Self Test
(POST). If you do not press <Delete> or <F2>, POST continues with its routines.
Entering BIOS Setup after POST
To enter BIOS Setup after POST:
• Press <Ctrl>+<Alt>+<Delete> simultaneously.
• Press the reset button on the system chassis.
• Press the power button to turn the system off then back on. Do this option only if you
failed to enter BIOS Setup using the rst two options.
After doing either of the three options, press <Delete> key to enter BIOS.
• Ensure that a USB mouse is connected to your motherboard if you want to use the
mouse to control the BIOS Setup program.
• If the system becomes unstable after changing any BIOS setting, load the default
settings to ensure system compatibility and stability. Select the Load Optimized
Defaults item under the Exit menu or press hotkey <F5>.
• If the system fails to boot after changing any BIOS setting, try to clear the CMOS and
reset the motherboard to the default value.
• The BIOS Setup program does not support Bluetooth devices.
BIOS menu screen
The BIOS Setup program can be used under two modes: EZ Mode and Advanced Mode.
You can change modes from Setup Mode in Boot menu or by pressing the <F7> hotkey.