Note the following details of the code protection feature on Microchip devices:
•Microchip products meet the specification contained in their particular Microchip Data Sheet.
•Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•Microchip is willing to work with the customer who is concerned about the integrity of their code.
•Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
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The Microchip name and logo, the Microchip logo, dsPIC,
KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART,
rfPIC and UNI/O are registered trademarks of Microchip
Technology Incorporated in the U.S.A. and other countries.
FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,
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logo, REAL ICE, rfLAB, Select Mode, Total
Endurance, TSHARC, UniWinDriver, WiperLock and ZENA
are trademarks of Microchip Technology Incorporated in the
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SQTP is a service mark of Microchip Technology Incorporated
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All other trademarks mentioned herein are property of their
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Microchip received ISO/TS-16949:2002 certification for its worldwide
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analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
®
MCUs and dsPIC® DSCs, KEELOQ
®
code hopping
DS39935C-page ii 2010 Microchip Technology Inc.
ENC424J600/624J600
Stand-Alone 10/100 Ethernet Controller
with SPI or Parallel Interface
• IEEE 802.3™ Compliant Fast Ethernet Controller
• Integrated MAC and 10/100Base-T PHY
• Hardware Security Acceleration Engines
• 24-Kbyte Transmit/Receive Packet Buffer SRAM
• Supports one 10/100Base-T Port with Automatic
Polarity Detection and Correction
• Supports Auto-Negotiation
• Support for Pause Control Frames, including
Automatic Transmit and Receive Flow Control
• Supports Half and Full-Duplex Operation
• Programmable Automatic Retransmit on Collision
• Programmable Padding and CRC Generation
• Programmable Automatic Rejection of Erroneous
and Runt Packets
• Factory Preprogrammed Unique MAC Address
•MAC:
- Support for Unicast, Multicast and Broadcast
packets
- Supports promiscuous reception
- Programmable pattern matching
- Programmable filtering on multiple packet
formats, including Magic Packet™, Unicast,
Multicast, Broadcast, specific packet match,
destination address hash match or any packet
•PHY:
- Wave shaping output filter
- Internal Loopback mode
- Energy Detect Power-Down mode
• Available MCU Interfaces:
- 14 Mbit/s SPI interface with enhanced set of
opcodes (44-pin and 64-pin packages)
- 8-bit multiplexed parallel interface
(44-pin and 64-pin packages)
- 8-bit or 16-bit multiplexed or demultiplexed
parallel interface (64-pin package only)
• Security Engines:
- High-performance, modular exponentiation
engine with up to 1024-bit operands
- Supports RSA
exchange algorithms
- High-performance AES encrypt/decrypt
engine with 128-bit, 192-bit or 256-bit key
- Hardware AES ECB, CBC, CFB and OFB
mode capability
- Software AES CTR mode capability
- Fast MD5 hash computations
- Fast SHA-1 hash computations
•Buffer:
- Configurable transmit/receive buffer size
- Hardware-managed circular receive FIFO
- 8-bit or 16-bit random and sequential access
- High-performance internal DMA for fast
memory copying
- High-performance hardware IP checksum
calculations
- Accessible in low-power modes
- Space can be reserved for general purpose
application usage in addition to transmit and
receive packets
• Operational:
- Outputs for two LED indicators with support
for single and dual LED configurations
- Transmit and receive interrupts
-25MHz clock
- 5V tolerant inputs
- Clock out pin with programmable frequencies
from 50 kHz to 33.3 MHz
- Operating voltage range of 3.0V to 3.6V
- Temperature range: -40°C to +85°C industrial
• Available in 44-Pin (TQFP and QFN) and 64-Pin
TQFP Package
11.0 Flow Control ............................................................................................................................................................................. 105
12.0 Speed/Duplex Configuration and Auto-Negotiation.................................................................................................................. 109
Index .................................................................................................................................................................................................. 159
The Microchip Web Site..................................................................................................................................................................... 163
Customer Change Notification Service .............................................................................................................................................. 163
Customer Support .............................................................................................................................................................................. 163
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
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When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are
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DS39935C-page 4 2010 Microchip Technology Inc.
ENC424J600/624J600
1.0DEVICE OVERVIEW
This document contains device-specific information for
the following devices:
• ENC424J600
• ENC624J600
The ENC424J600 and ENC624J600 are stand-alone,
Fast Ethernet controllers with an industry standard
Serial Peripheral Interface (SPI) or a flexible parallel
interface. They are designed to serve as an Ethernet
network interface for any microcontroller equipped with
SPI or a standard parallel port.
ENC424J600/624J600 devices meet all of the
IEEE 802.3 specifications applicable to 10Base-T and
100Base-TX Ethernet, including many optional
clauses, such as auto-negotiation. They incorporate a
number of packet filtering schemes to limit incoming
packets. They also provide an internal, 16-bit wide
DMA for fast data throughput and support for hardware
IP checksum calculations.
For applications that require the security and authentication features of SSL, TLS and other protocols related
to cryptography, a block of security engines is provided.
The engines perform RSA, Diffie-Hellman, AES, MD5
and SHA-1 algorithm computations, allowing reduced
code size, faster connection establishment and
throughput, and reduced firmware development effort.
Communication with the microcontroller is
implemented via the SPI or parallel interface, with data
rates ranging from 14 Mbit/s (SPI) to 160 Mbit/s
(demultiplexed, 16-bit parallel interface). Dedicated
pins are used for LED link and activity indication and for
transmit/receive/DMA interrupts.
A generous 24-Kbyte on-chip RAM buffer is available
for TX and RX operations. It may also be used by the
host microcontroller for general purpose storage.
Communication protocols, such as TCP, can use this
memory for saving data which may need to be
retransmitted.
For easy end product manufacturability, each
ENC624J600 family device is preprogrammed with a
unique nonvolatile MAC address. In most cases, this
allows the end device to avoid a serialized
programming step.
The only functional difference between the
ENC424J600 (44-pin) and ENC624J600 (64-pin)
devices are the number of parallel interface options
they support. These differences, along with a summary
of their common features, are provided in Table 1-1. A
general block diagram for the devices is shown in
Figure 1-1.
A list of the pin features, sorted by function, is
presented in Table 1-2.
TABLE 1-1:DEVICE FEATURES FOR ENC424J600/624J600
FeatureENC424J600ENC624J600
Pin Count4464
Ethernet Operating Speed10/100 Mbps (auto-negotiate, auto-sense or manual)
Ethernet Duplex ModesHalf and Full (auto-negotiate and manual)
Ethernet Flow ControlPause and Backpressure (auto and manual)
Buffer Memory (bytes) 24K (organized as 12K word x 16)
Internal Interrupt Sources11 (mappable to a single external interrupt flag)
Serial Host Interface (SPI)YesYes
Parallel Host Interface:
Operating modes28
Muliplexed, 8-bitYesYes
16-bitNoYes
Demultiplexed, 8-bitNoYes
16-bitNoYes
Cryptographic Security Options:
AES, 128/192/256-bitYesYes
MD5/SHA-1YesYes
Modular Exponentiation, 1024-bitYesYes
Receive Filter OptionsAccept or reject packets with CRC match/mismatch, runt error collect
or reject, Unicast, Not-Me Unicast, Multicast, Broadcast,
Magic Packet™, Pattern Table and Hash Table
Packages 44-Pin TQFP, QFN64-Pin TQFP
2010 Microchip Technology Inc.DS39935C-page 5
ENC424J600/624J600
24 Kbytes
DMA and
Checksum
TX Control
RX Control
Arbiter
Flow Control
Host Interface
Control
Registers
25 MHz
Power-on
PHY
MII
Interface
MIIM
Interface
TPOUT+
TPOUT-
TPIN+
TPIN-
TX
RX
RBIAS
OSC1
OSC2
Control Logic
CS/CS
SI/RD/RW
SO
SCK/AL
INT
VCAP
CLKOUT
LEDA
LEDB
RX Filter
MAC
m3
m1
SRAM
Note 1: A<14:0>, AD15, WRL/B0SEL, WRH/B1SEL and PSPCFG<4:1> are available on 64-pin devices only. PSPCFG0 is available on 44-pin
TPIN-1727IANADifferential Ethernet Receive Minus Signal Input
TPIN+1626IANADifferential Ethernet Receive Plus Signal Input
TPOUT-2131O—Differential Ethernet Transmit Minus Signal Output
TPOUT+2030O—Differential Ethernet Transmit Plus Signal Output
CAP4363P—Regulator External Capacitor connection
V
VDD4421, 47,
VDDOSC44P—Positive 3.3V Power Supply for 25 MHz Oscillator
VDDPLL1222P—Positive 3.3V Power Supply for PHY PLL Circuitry
VDDRX1525P—Positive 3.3V Power Supply for PHY RX Circuitry
VDDTX1828P—Positive 3.3V Power Supply for PHY TX Circuitry
VSS33, 4246, 62P—Ground Reference for Digital Logic
VSSOSC11P—Ground Reference for 25 MHz Oscillator
VSSPLL1323P—Ground Reference for PHY PLL Circuitry
VSSRX1424P—Ground Reference for PHY RX Circuitry
VSSTX19, 2229, 32P—Ground Reference for PHY TX Circuitry
WR3550ICMOSPSP Write Strobe
WRH—48ICMOSPSP Write High Strobe
WRL—50ICMOSPSP Write Low Strobe
Legend: I = Input; O = Output; P = Power; CMOS = CMOS compatible input buffer; ANA = Analog level input/output
Pin Number
Pin Type
44-Pin64-Pin
3651ICMOSPSP Combined Read/Write Signal
P—Positive 3.3V Power Supply for Digital Logic
64
Input
Buffer
Description
DS39935C-page 8 2010 Microchip Technology Inc.
ENC424J600/624J600
C1
(3)
C2
(3)
XTAL
OSC2
RS
(1)
OSC1
RF
(2)
To Internal Logic
Note 1: A series resistor, RS, may be required for
crystals with a low drive strength specification
or when using large loading capacitors.
2: The feedback resistor, RF , is typically 1.5 M
approx.
3: The load capacitors’ value should be derived
from the capacitive loading specification
provided by the crystal manufacture.
ENCX24J600
3.3V Clock from
External System
(1)
OSC1
OSC2
Open
Note 1: Duty cycle restrictions must be observed.
ENCX24J600
2.0EXTERNAL CONNECTIONS
2.1Oscillator
ENC424J600/624J600 devices are designed to
operate from a fixed 25 MHz clock input. This clock can
be generated by an external CMOS clock oscillator or
a parallel resonant, fundamental mode 25 MHz crystal
attached to the OSC1 and OSC2 pins. Use of a crystal,
rated for series resonant operation, will oscillate at an
incorrect frequency. To comply with IEEE 802.3 Ethernet
timing requirements, the clock must have no more than
±50 ppm of total error; avoid using resonators or clock
generators that exceed this margin.
When clocking the device using a crystal, follow the
connections shown in Figure 2-1. When using a CMOS
clock oscillator or other external clock source, follow
Figure 2-2.
FIGURE 2-1:CRYSTAL OSCILLATOR
OPERATION
FIGURE 2-2:EXTERNAL CLOCK
SOURCE
2.2CLKOUT Pin
The Clock Out pin (CLKOUT) is provided for use as the
host controller clock or as a clock source for other
devices in the system. Its use is optional.
The 25 MHz clock applied to OSC1 is multiplied by a
PLL to internally generate a 100 MHz base clock. This
100 MHz clock is driven through a configurable
postscaler to yield a wide range of different CLKOUT
frequencies. The PLL multiplication adds clock jitter,
subject to the PLL jitter specification in Section 17.0“Electrical Characteristics”. However, the postscaler
ensures that the clock will have a nearly ideal duty
cycle.
The CLKOUT function is enabled and the postscaler is
selected via the COCON<3:0> bits (ECON2<11:8>).
To create a clean clock signal, the CLKOUT output and
COCON bits are unaffected by all resets and
power-down modes. The CLKOUT function is enabled
out of POR and defaults to producing a 4 MHz clock.
This allows the device to directly clock the host
processor.
When the COCON bits are written with a new
configuration, the CLKOUT output transitions to the
new frequency without producing any glitches. No high
or low pulses with a shorter period than the original or
new clock are generated.
2010 Microchip Technology Inc.DS39935C-page 9
ENC424J600/624J600
VDD
VCAP
VSS
ENCX24J600
10 F
3.3V
0.1 F
Regulator
+3.3V
I/O, PHY
+1.8V
Core, RAM,
MAC
RBIAS
ENCX24J600
12.4k
1%
PHY
2.3Voltage and Bias Pin
2.3.1VDD AND VSS PINS
To reduce on-die noise levels and provide for the
high-current demands of Ethernet, there are many
power pins on ENC424J600/624J600 devices:
•VDD and VSS
•VDDOSC and VSSOSC
•VDDPLL and VSSPLL
•VDDRX and VSSRX
•VDDTX and VSSTX
Each VDD and VSS pin pair above should have a 0.1 F
ceramic bypass capacitor placed as close to the pins as
possible. For best EMI emission suppression, other
smaller capacitors, such as 0.001 F, should be placed
immediately across V
All VDD power supply pins must be externally connected to the same 3.3V ±10% power source. Similarly,
all VSS supply references must be externally connected
to the same ground node. If a ground connection
appears on two pins (e.g., V
do not allow either to float. In addition, it is
recommended that the exposed bottom metal pad on
the 44-pin QFN package be tied to VSS.
Placing ferrite beads or inductors between any two of
the supply pins (e.g., between VDDOSC and VDDRX) is
not recommended. However, it is acceptable to isolate
DD
all of the V
supplies from the main circuit power supply through a single ferrite bead or inductor, if desired
for supply noise suppression reasons. Such isolation is
generally not necessary.
DDTX/VSSTX and VDDPLL/VSSPLL.
SSTX), connect both pins;
FIGURE 2-3:VCAP CONNECTIONS
2.3.3RBIAS PIN
The internal analog circuitry in the PHY module
requires that an external 12.4 kΩ, 1% resistor be
attached from RBIAS to ground, as shown in
Figure 2-4. The resistor influences the TPOUT+/signal amplitude. The RBIAS resistor should be placed
as close as possible to the chip with no immediately
adjacent signal traces in order to prevent noise
capacitively coupling into the pin and affecting the
transmit behavior. It is recommended that the resistor
be a surface mount type.
FIGURE 2-4:RBIAS RESISTOR
2.3.2VCAP PIN
Most of the device’s digital logic operates at a nominal
1.8V. This voltage is supplied by an on-chip voltage
regulator, which generates the digital supply voltage
from the VDD rail. The only external component
required is an external filter capacitor, connected from
the VCAP pin to ground, as shown in Figure 2-3. A value
of at least 10 F is recommended.
The capacitor must also have a relatively low Equivalent Series Resistance (ESR). It is recommended that
a low-ESR capacitor (ceramic, tantalum or similar)
should be used and high-ESR capacitors (such as
aluminum electrolytic) should be avoided.
The internal regulator is not designed to drive external
loads; therefore, do not attach other circuitry to V
DS39935C-page 10 2010 Microchip Technology Inc.
CAP.
ENC424J600/624J600
ENCX24J600
TPOUT+
TPOUT-
TPIN+
TPIN-
3.3V
1
2
3
4
5
6
7
8
RJ-45
1:1 CT
1:1 CT
1000 pF, 2 kV
75757575
49.9, 1%
49.9
, 1%
49.9, 1%
49.9, 1%
0.01 F
0.01
F
1
6.8 n
F, 1 0 %
6.8 n
F, 1 0 %
10, 1/12W, 1%
2.4Ethernet Signal Pins and External
Magnetics
Typical applications for ENC424J600/624J600 devices
require an Ethernet transformer module, and a few
resistors and capacitors to implement a complete
IEEE 802.3 compliant 10/100 Ethernet interface, as
shown in Figure 2-5.
The Ethernet transmit interface consists of two pins:
TPOUT+ and TPOUT-. These pins implement a
differential pair and a current-mode transmitter. To
generate an Ethernet waveform, ordinary applications
require the use of a 1:1 center tapped pulse
transformer, rated for 10/100 or 10/100/1000 Ethernet
operations. When the Ethernet module is enabled and
linked with a partner, current is continually sunk
through both TPOUT pins. When the PHY is actively
transmitting, a differential voltage is created on the
Ethernet cable by varying the relative current sunk by
TPOUT+ compared to TPOUT-.
The Ethernet receive interface similarly consists of a
differential pair: TPIN+ and TPIN-. To meet IEEE 802.3
compliance and help protect against electrostatic discharge, these pins are normally isolated from the
Ethernet cable by a 1:1 center tapped transformer
(available in the same package as the TX transformer).
Internally, the PHY uses a high-speed ADC to sample
the receive waveform and decodes it using a DSP. The
PHY implements many robustness features, including
baseline wander correction (applicable to 100Base-TX)
and automatic RX polarity correction (applicable to
10Base-T).
Four 49.9Ω, 1% resistors are required for proper
termination of the TX and RX transmission lines. If the
board layout necessitates long traces between the
ENCX24J600 and Ethernet transformers, the termination resistors should be placed next to the silicon
instead of the transformers.
On the receive signal path, two 6.8 nF 10% capacitors
are used. These capacitors, in combination with the
49.9 termination resistors, form an RC high-pass filter
to reduce baseline wander. For best performance,
these capacitors should not be omitted or changed.
The various remaining capacitors provide DC current
blocking and provide stability to the common-mode
voltage of both of the differential pairs. The TPIN+/pins weakly output a common-mode voltage that is
acceptable to the internal ADC. For proper operation,
do not attempt to externally force the TPIN+/common-mode voltage to some other value.
The 10Ω 1% resistor provides a current path from the
power supply to the center tap of the TX transformer.
As mentioned previously, the TPOUT+/- pins
implement a Current mode drive topology in which the
pins are only capable of sinking current; they do not
produce a direct voltage. This current path through the
transformer generates the transmit waveform. The 10Ω
resistor reduces the amount of heat that the PHY would
have to dissipate, and therefore, must have a power
rating of 1/12W or better.
FIGURE 2-5:TYPICAL ETHERNET MAGNETICS CONNECTIONS
2010 Microchip Technology Inc.DS39935C-page 11
ENC424J600/624J600
1:1 CT
PHY
RJ-45
180
LEDA
or
LEDB
LED
180
LEDA
LEDB
LED
Bi-Color
2.4.1ADDITIONAL EMI AND LAYOUT
CONSIDERATIONS
To reduce EMI emissions, common-mode chokes are
shown adjacent to the transformers on the cable
(RJ-45) side. These chokes come standard in typical
Ethernet transformer modules. Because the
ENCX24J600 PHY uses a current-mode drive topology, the transmit choke must normally be located on
the cable side of the transmit transformer. Orienting the
magnetics such that the choke is on the PHY side of the
transmit transformer usually results in a distorted,
non-compliant transmit waveform. However, some
magnetics which wrap the TX center tap wire around
the TX choke core can also be used to generate a
compliant waveform (Figure 2-6). These types of transformers may be desirable in some Power-over Ethernet
(PoE) applications.
By default on POR, LEDA displays the Ethernet link
status, while LEDB displays PHY-level TX/RX activity.
Because the LEDs operate at the PHY level, RX
activity will be displayed on LEDB any time Ethernet
packets are detected, regardless of if the packet is valid
and meets the correct RX filtering criteria.
Normally, the device illuminates the LED by sourcing
current out of the pin, as shown in Figure 2-7. Connecting the LED in reverse, with the anode connected to
DD
and the cathode to LEDA/LEDB (through a
V
current-limiting resistor), causes the LED to show
“inverted sense” behavior, lighting the LED when it
should be off and extinguishing the LED when the LED
should be on.
FIGURE 2-7:SINGLE COLOR LED
CONNECTION
FIGURE 2-6:ALTERNATE TX CHOKE
TOP OL O G Y
Both LEDs automatically begin operation whenever
power is applied, a 25 MHz clock is present and the
Ethernet magnetics are present and wired correctly. A
connection to the host microcontroller via the SPI or
The common-mode choke on the RX interface can be
placed on either the cable side or PHY side of the
receive transformer. Recommended and required magnetics characteristics are located in Section 17.0“Electrical Characteristics”.
The four 75Ω resistors and high-voltage capacitor in
Figure 2-5 are intended to prevent each of the twisted
pairs in the Ethernet cables from floating and radiating
EMI. Their implementation may require adjustment in
PoE applications.
Unless the TX and RX signal pairs are kept short, they
should be routed between the ENCX24J600 and the
Ethernet connector following differential routing rules.
Like Ethernet cables, 100Ω characteristic impedance
should be targeted for the differential traces. The use of
vias, which introduce impedance discontinuities,
should be minimized. Other board level signals should
not run immediately parallel to the TX and RX pairs to
minimize capacitive coupling and crosstalk.
2.5LEDA and LEDB Pins
The LEDA and LEDB pins provide dedicated LED
status indicator outputs. The LEDs are intended to
display link status and TX/RX activity among other
programmable options; however, the use of one or both
is entirely optional. The pins are driven automatically by
the hardware and require no support from the host
microcontroller. Aside from the LEDs themselves, a
current-limiting resistor is generally the only required
component.
DS39935C-page 12 2010 Microchip Technology Inc.
PSP interface is not required. LEDA and LEDB can,
therefore, be used as a quick indicator of successful
assembly during initial prototype development.
2.5.1USING BI-COLOR LEDs
In space constrained applications, it is frequently desir-
able to use a single bi-color LED to display multiple
operating parameters. These LEDs are connected
between LEDA and LEDB, as shown in Figure 2-8.
FIGURE 2-8:BI-COLOR LED
CONNECTION
ENCX24J600 devices include two special hardware
display modes to make maximal use of a bi-color LED.
These modes are selected when the LACFG<3:0> and
LBCFG<3:0> bits (EIDLED<15:8>) are set to ‘1111’ or
‘1110’. In these configurations, the link state turns the
LED on, the speed/duplex state sets the LED color and
TX/RX events cause the LED to blink off. If a link is
present, no TX/RX events are occurring and the
speed/duplex state is 100 Mbps/full duplex,
respectively, then the LEDB pin will be driven high while
LEDA will be driven low.
ENC424J600/624J600
I/O
SCK
SDO
SDI
INT0
MCU
CS
SCK
SI
SO
INT
/SPISEL
ENCX24J600
3.3V
100k
PMALL
PMCS2
RMRD
PMWR
INT0
MCU
AL
CS
RD
WR
INT
/SPISEL
ENCX24J600
ADx
PMAx/PMDx
100k
SPI SelectedPSP Selected (Mode 5 shown)
~2.2V
VSS
(internal weak pull-up on CS
enabled)(internal weak pull-down on CS enabled)
2.6I
The INT
NT Pin
pin is an active-low signal that is used to flag
interrupt events to external devices. Depending on the
application, it can be used to signal the host microcontroller whenever a packet has been received or
transmitted, or that some other asynchronous
operation has occurred. It can also be used to wake-up
the microcontroller or other system components based
on LAN activity; its use is optional.
The INT pin is driven high when no interrupt is pending
and is driven low when an interrupt has occurred. It
does not go into a high-impedance state, except during
initial power-on while the multiplexed SPISEL pin
function is being used.
Since ENC424J600/624J600 devices incorporate a
buffer for storing transmit and receive packets, the host
microcontroller never needs to perform real-time
operations on the device. The microcontroller can poll
the device registers to discover if the device status has
changed.
2.7Host Interface Pins
For the maximum degree of flexibility in interfacing with
microcontrollers, ENC424J600/624J600 devices offer
a choice between a serial interface based on the Serial
Peripheral Interface (SPI) standard, and a flexible 8 or
16-bit parallel slave port (PSP) interface. Only one
interface may be used at any given time.
The I/O interface is hardware selected on power-up
using the SPISEL function on the INT/SPISEL pin. This
is done by latching in the voltage level applied to the pin
approximately 1 to 10 s after power is applied to the
device and the device exits Power-on Reset. If SPISEL
is latched at a logic high state, the serial interface is
enabled. If SPISEL is latched at a logic low state, the
PSP interface is enabled. Figure 2-9 shows example
connections required to select the SPI or PSP interface
upon power-up.
To ensure the SPI interface is selected upon power-up,
an external pull-up resistor to VDD must be connected
to the SPISEL pin. Alternatively, if the parallel interface
is to be used, a pull-down resistor to V
SS must be
connected to the SPISEL pin. In most circuits, it is recommended that a 100 kΩ or smaller resistor be used to
ensure that the correct logic level is latched in reliably.
If a large capacitance is present in the SPISEL circuit,
such as from stray capacitance, a smaller pull-up or
pull-down resistor may be required to compensate and
ensure the correct level is sensed during power-up.
As SPISEL is multiplexed with the INT
interrupt output
function, a direct connection to VDD or VSS without a
resistor is prohibited. If INT
is connected to the host
microcontroller, the microcontroller must leave this
signal in a high-impedance state and not attempt to
drive it to an incorrect logic state during power-up.
DD supply has a slow ramp rate, the device will
If the V
exit POR, exceed the 1 to 10 s latch timer and sample
the SPISEL pin state before VDD has reached the specified minimum operating voltage of the device. In this
case, the device will still latch in the correct value,
assuming the minimum VIH (D004) or maximum VIL
(D006) specification is met, which is a function of VDD.
FIGURE 2-9:USING THE INT
/SPISEL PIN TO SELECT THE I/O INTERFACE
2010 Microchip Technology Inc.DS39935C-page 13
ENC424J600/624J600
2.7.1SPI
When enabled, the SPI interface is implemented with
four pins:
•CS
•SO
•SI
•SCK
All four of these pins must be connected to use the SPI
interface.
, SI and SCK input pins are 5V tolerant. The SO
The CS
pin is also 5V tolerant when in a high-impedance state.
SO is always high-impedance when CS
logic high (i.e., chip not selected).
When the SPI interface is enabled, all PSP interface
pins (except PSPCFG2 and PSPCFG3 on
ENC624J600 devices) are unused. They are placed in
a high-impedance state and their input buffers are disabled. For best ESD performance, it is recommended
that the unused PSP pins be tied to either V
However, these pins may be left floating if it is desirable
for board level layout and routing reasons.
When using an ENC624J600 device in SPI mode, it is
recommended that the PSPCFG2 and PSPCFG3 pins
SS
be tied to either V
be left floating. The particular state used is unimportant.
or any logic high voltage, and not
is connected to
SS or VDD.
2.7.2PSP
Depending on the particular device, the PSP interface
is implemented with up to 34 pins. The interface is
highly configurable to accommodate many different
parallel interfaces; not all available pins are used in
every configuration. Up to 8 different operating modes
are available. These are explained in detail in
Section 5.0 “Parallel Slave Port Interface (PSP)”.
The PSPCFG pins control which parallel interface
mode is used. The values on these pins are latched
upon device power-up in the same manner as the
SPISEL pin. The combinations of V
ages on the different PSPCFG mode pins determine
the PSP mode according to Table 2-1.
On ENC424J600 devices, only PSP Modes 5 and 6
(8-bit width, multiplexed data and address) are
available. The mode is selected by applying V
VDD, respectively, to PSPCFG0.
On ENC624J600 devices, all eight PSP modes are
available and are selected by connecting the
PSPCFG<4:1> pins directly to V
mode selection is encoded such that the multiplexed
pin functions, AD14 (on PSPCFG1) and SCK/AL (on
PSPCFG4), are used only in the “don’t care” positions.
Therefore, pull-up/pull-down resistors are not required
for these pins.
All PSP pins, except for AD<15:0>, are inputs to the
ENC624J600 family device and are 5V tolerant. The
AD<15:0> pins are bidirectional I/Os and are 5V
tolerant in Input mode. The pins are always inputs
when the CS signal is low (chip not selected).
Any unused PSP pins are placed in a high-impedance
state. However, it is recommended that they be tied to
either Vss or a logic high voltage and not be left floating.
DD and VSS volt-
SS or
DD or ground. The
TABLE 2-1:PSP MODE SELECTION FOR ENC424J600/624J600 DEVICES
Legend: x = don’t care, 0 = logic low (tied to VSS), 1 = logic high (tied to VDD), — = pin not present
INT
/SPISEL
01234
PSPCFG
Pins Used
44-Pin
64-Pin
, EN, A14:A0, AD<7:0>
, EN, AD<14:0>
, B0SEL, B1SEL, AD<15:0>
DS39935C-page 14 2010 Microchip Technology Inc.
ENC424J600/624J600
I/O
SCK
SDO
SDI
INTx
MCU
CS
SCK
SI
SO
INT
/SPISEL
ENCX24J600
CLKOUT
OSC1
3.3V
100k
I/O
SCK
SDO
SDI
INTx
MCU
CS
SCK
SI
SO
INT
/SPISEL
ENCX24J600
CLKOUT
OSC1
3.3V
100k
2.7.3CS
/CS PIN
The chip select functions for the serial and parallel
interfaces are shared on one common pin, CS
/CS. This
pin is equipped with both internal weak pull-up and
weak pull-down resistors. If the SPI interface is
selected (CS
), the pull-up resistor is automatically
enabled and the pull-down resistor is disabled. If the
PSP interface is chosen (CS), the pull-down resistor is
automatically enabled and the pull-up resistor is
disabled. This allows the CS
/CS pin to stay in the
unselected state when not being driven, avoiding the
need for an external board level resistor on this pin.
When enabled by using SPI mode, the internal weak
pull-up only pulls the CS
/CS pin up to approximately
VDD-1.1V or around 2.2V at typical conditions without
any loading; it does not pull all the way to VDD. When
using the PSP interface, the pull-down will be enabled,
which is capable of pulling all the way to VSS when
unloaded.
2.8Digital I/O Levels
All digital output pins on ENC424J600/624J600
devices contain CMOS output drivers that are capable
of sinking and sourcing up to 18 mA continuously. All
digital inputs and I/O pins operating as inputs are 5V
tolerant. These features generally mean that the
ENCX24J600 can connect directly to the host
microcontroller without the need of any glue logic.
However, some consideration may be necessary when
interfacing with 5V systems.
Since the digital outputs drive only up to the V
voltage (3.3V nominally), the voltage may not be high
enough to ensure a logical high is detected by 5V
systems which have high input thresholds. In such
cases, unidirectional level translation from the 3.3V
ENCX24J600 up to the 5V host microcontroller may be
needed.
When using the SPI interface, an economical 74HCT08
(quad AND gate), 74ACT125 (quad 3-state buffer) or
other 5V CMOS chip with TTL level input buffers may
be used to provide the necessary level shifting. The
use of 3-state buffers permits easy integration into
systems which share the SPI bus with other devices.
However, users must make certain that the propagation delay of the level translator does not reduce the
maximum SPI frequency below desired levels.
Figure 2-10 and Figure 2-11 show two example
translation schemes.
When using the PSP interface, eight, or all sixteen of
the ADx pins, may need level translation when performing read operations on the ENCX24J600. The 8-bit
74ACT245 or 16-bit 74ACT16245 bus transceiver, or
similar devices, may be useful in these situations.
DD
FIGURE 2-10:LEVEL SHIFTING ON THE
SPI INTERFACE USING
AND GATES
FIGURE 2-11:LEVEL SHIFTING ON THE
SPI INTERFACE USING
3-STATE BUFFERS
2010 Microchip Technology Inc.DS39935C-page 15
ENC424J600/624J600
NOTES:
DS39935C-page 16 2010 Microchip Technology Inc.
ENC424J600/624J600
0000h
5FFFh
00h
SRAM Buffer
Unimplemented
7800h
7C4Fh
Bank 0
Bank 1
Bank 2
Bank 3
Unbanked
(inaccessible using
banked opcodes)
1Fh
20h
3Fh
40h
5Fh
60h
7Fh
80h
9Fh
00h
1Fh
00h
1Fh
00h
1Fh
00h
1Fh
Cryptographic Data
(DMA access only)
Unimplemented
7FFFh
16-Bit, MIIM Access Only
00h
1Fh
PHY Register
MIREGADR
Banked Opcodes
Unbanked Opcodes
Pointers
SFR Area
Main Area
Area
3.0MEMORY ORGANIZATION
All memory in ENC424J600/624J600 devices is
implemented as volatile RAM. Functionally, there are
four unique memories:
• Special Function Registers (SFRs)
• PHY Special Function Registers
• Cryptographic Data Memory
•SRAM Buffer
The SFRs configure, control and provide status
information for most of the device. They are directly
accessible through the I/O interface.
The PHY SFRs configure, control and provide status
information for the PHY module. They are located
inside the PHY module and isolated from all other
normal SFRs, so they are not directly accessible
through the I/O interface.
The cryptography data memory is used to store key
and data material for the modular exponentiation, AES
and MD5/SHA-1 hashing engines. This memory area
can only be accessed through the DMA module.
The SRAM buffer is a bulk 12K x 16-bit (24 Kbyte) RAM
array used for TX and RX packet buffering, as well as
general purpose storage by the host microcontroller.
Although the SRAM uses a 16-bit word, it is
byte-writable. This memory is indirectly accessible
through pointers on all I/O interfaces. It can also be
accessed directly through the PSP interfaces.
3.1I/O Interface and Memory Map
Depending on the I/O interface selected, the four
memories are arranged into two or three different memory
address spaces. When the serial interface is selected, the
memories are grouped into three address spaces. When
one of the parallel interfaces is selected, they are
arranged into two address spaces. In all cases, the PHY
SFRs reside in their own memory address space.
3.1.1SPI INTERFACE MAP
When the SPI interface is selected, the device memory
map is comprised of three memory address spaces
(Figure ):
• the SFR area
• the main memory area
• the PHY register area
The SFR area is directly accessible to the user. This is
a linear memory space that is 160 bytes long. For
efficiency, the SFR area can be addressed as four
banks of 32 bytes each, starting at the beginning of the
space (00h), with an additional unbanked area of
32 bytes at the end of the SFR memory. Banked
addressing allows SFRs to be addressed with fewer
address bits being exchanged over the serial interface
for each transaction. This decreases protocol overhead
and enhances performance. SFRs can also be directly
addressed by their 8-bit unbanked addresses using
unbanked SPI commands. This allows for a simpler
interface whenever transaction overhead is not critical.
The main memory area is organized as a linear,
byte-addressable space of 32 Kbytes. Of this, the first
24-Kbyte area (0000h through 5FFFh) is implemented
as the SRAM buffer. The buffer is accessed by the
device using several SFRs as memory pointers and
virtual data window registers, as described in
Section 3.5.5 “Indirect SRAM Buffer Access”.
Addresses in the main memory area, between 7800h
and 7C4Fh, are mapped to the memory for the cryptographic data modules. These addresses are not
directly accessible through the SPI interface; they can
only be accessed through the DMA.
The PHY SFRs are the final memory space. This is a
linear, word-addressable memory space of 32 words.
This area is only accessible by the MIIM interface (see
Section 3.3 “PHY Special Function Registers” for
more details).
FIGURE 3-1:ENC424J600/624J600 MEMORY MAP WITH SPI INTERFACE
2010 Microchip Technology Inc.DS39935C-page 17
ENC424J600/624J600
0000h
2FFFh
SRAM Buffer
Unimplemented
Cryptographic Data
(DMA access only)
3F00h
Unimplemented
Special Function Registers (R/W)
3F4Fh
0000h
5FFFh
7800h
(2)
7C4Fh
(2)
PSP Address Bus (Word Address)
Pointers (Byte Address)
16-Bit, MIIM Access Only
00h
1Fh
PHY Register Area
MIREGADR
3F80h
SFR Bit Set Registers
3FBFh
3FC0h
SFR Bit Clear Registers
3FFFh
16-Bit, MIIM Access Only
00h
1Fh
PHY Register Area
MIREGADR
0000h
5FFFh
SRAM Buffer
Unimplemented
7800h
(2)
7C4Fh
(2)
Cryptographic Data
(DMA access only)
7E00h
Unimplemented
Special Function
Registers (R/W)
7E9Fh
PSP Address Bus and
All Pointers
7F00h
SFR Bit Set Registers
7F7Fh
7F80h
SFR Bit Clear Registers
7FFFh
Main AreaMain Area
8-Bit PSP16-Bit PSP
Note 1:Memory areas not shown to scale.
2:Addresses in this range are accessible only through internal address pointers of the DMA module.
3.1.2PSP INTERFACE MAPS
When one of the parallel interfaces is selected, the
memory map is very different from the SPI map. There
are two different memory address spaces (Figure 3-2):
• the main memory area
• the PHY register area
As in the serial memory map, the main memory area is
a linear, byte-addressable space of 32 Kbytes, with the
SRAM buffer located in the first 24-Kbyte region. The
cryptographic data memory is also mapped to the same
location as in the serial memory map. The main difference is that the SFRs are now located to an area with a
higher address than the cryptographic data space. Additional memory areas above the SFRs are reserved for
their accompanying Bit Set and Bit Clear registers.
Except for the cryptographic data memory, all
addresses in the main memory area are directly
accessible using the PSP bus. As with the serial interface, the cryptographic memory can only be accessed
through the DMA.
The difference between the 8-bit and 16-bit interfaces is
how the SRAM buffer is addressed by the external
address bus. In 16-bit data modes, the address bus
treats the buffer as a 16-byte wide, word-addressable
space, spanning 000h to 3FFFh. In 8-bit data modes, the
address bus treats the buffer as an 8-bit, byte-addressable space, ranging from 0000h to 7FFFh. In either case,
the SFRs used as memory pointers still address the
buffer as a byte-wide, byte-addressable space.
The PHY SFR space is implemented in the same
manner as the SPI interface described above.
In both 8-bit and 16-bit PSP modes, full device functionality can be realized without using the full width of
the address bus. This is because the SRAM buffer can
still be read and written to by using SFR pointers. In
practical terms, this can allow designers in space or pin
constrained applications to only connect a subset of the
A or AD address pins to the host microcontroller. For
example, in the 8-Bit Multiplexed PSP Modes 5 or 6,
tying pins, AD<14:9> to V
DD, still allows direct address
access to all SFRs. This reduces the number of pins
required for connection to the host controller, including
the interface control pins to 12 or 13.
FIGURE 3-2:ENC424J600/624J600 MEMORY MAPS FOR PSP INTERFACES
(1)
DS39935C-page 18 2010 Microchip Technology Inc.
ENC424J600/624J600
3.2Special Function Registers
The SFRs provide the main interface between the host
controller and the on-chip Ethernet controller logic.
Writing to these registers controls the operation of the
interface, while reading the registers allows the host
controller to monitor operations.
All registers are 16 bits wide. On the SPI and 8-bit PSP
interfaces, which are inherently byte-oriented, the
registers are split into separate high and low locations
which are designated by an “H” or “L” suffix, respectively. All registers are organized in little-endian format
such that the low byte is always at the lower memory
address.
Some of the available addresses are unimplemented or
marked as reserved. These locations should not be
written to. Data read from reserved locations should be
ignored. Reading from unimplemented locations will
return ‘0’. When reading and writing to registers which
contain reserved bits, any rules stated in the register
definition should be observed.
The addresses of all user-accessible registers are
provided in Tables 3-1 through 3-6. A complete bit level
listing of the SFRs is presented in Table 3-7 (page 26).
3.2.1 E REGISTERS
SFRs with names starting with “E” are the primary
control and pointer registers. They configure and control all of the (non-MAC) top-level features of the
device, as well as manipulate the pointers that define
the memory buffers. These registers can be read and
written in any order, with any length, without concern
for address alignment.
3.2.3SPI REGISTER MAP
As previously described, the SFR memory is
partitioned into four banks plus a special region that is
not bank addressable. Each bank is 32 bytes long and
addressed by a 5-bit address value. All SFR memory
may also be accessed via unbanked SPI opcodes
which use a full 8-bit address to form a linear address
map without banking.
The last 10 bytes (16h to 1Fh) of all SPI banks point to
a common set of five registers: EUDAST, EUDAND,
ESTAT, EIR and ECON1. These are key registers used
in controlling and monitoring the operation of the
device. Their common banked addresses allow easy
access without switching the bank.
The SPI interface implements a comprehensive
instruction set that allows for reading and writing of
registers, as well as setting and clearing individual bits
or bit fields within registers. The SPI instruction set is
explained in detail in Section 4.0 “Serial PeripheralInterface (SPI)”.
The SFR map for the SPI interface is shown in
Table 3-1. Registers are presented by a bank. The
banked (5-bit) address applicable to the registers in
each row is shown in the left most column. The
unbanked (8-bit) address for each register is shown to
the immediate left of the register name.
Note:SFRs in the unbanked region (80h through
9Fh) cannot be accessed using banked
addressing. The use of an unbanked SFR
opcode is required to perform operations
on these registers.
3.2.2MAC REGISTERS
SFRs with names that start with “MA” or “MI” are
implemented in the MAC module hardware. For this
reason, their operation differs from “E” registers in two
ways.
First, MAC registers support read and write operations
only. Individual bit set and bit clear operations cannot
be performed.
Additionally, MAC registers must always be written as
a 16-bit word, regardless of the I/O interface being
used. That is, on the SPI or 8-bit PSP interfaces, all
write operations must be performed by writing to the
low byte, followed by a write to the associated high
byte. On 16-bit PSP interfaces, both write enables or
byte selects must be asserted to perform the 16-bit
write. Non-sequential writes, such as writing to the low
byte of one MAC register, the low byte of a second
MAC register and then the high byte of the first register
cannot be performed.
Note 1:Unbanked SFRs can be accessed only by unbanked SPI opcodes.
Unbanked
2:When using these registers to access the SRAM buffer, use only the N-byte SRAM instructions. See Section 4.6.2
Name
Address
“Unbanked SFR Operations” and Section 4.6.3 “SRAM Buffer Operations” for more details.
Name
Address
Unbanked
Unbanked
Name
Address
Unbanked
Name
Address
Unbanked
Name
Address
—
—
(2)
(2)
(2)
DS39935C-page 20 2010 Microchip Technology Inc.
ENC424J600/624J600
3.2.4PSP REGISTER MAP
When using a PSP interface, the SFR memory is linear;
The SFR maps for the 8-bit and 16-bit PSP interfaces
are shown in Table 3-2 and Table 3-3, respectively.
all registers are directly accessible without banking. To
maintain consistency with the SPI interface, the
EUDAST, EUDAND, ESTAT, EIR and ECON1 registers
are instantiated in four locations in the PSP memory
maps. Users may opt to use any one of these four
locations.
A major difference between the SPI and PSP memory
maps is the inclusion of companion Bit Set and Bit
Clear registers for many of the E registers. Since the
PSP interface allows direct access to memory
locations, without a command interpreter, there are no
instructions implemented to perform single bit
manipulations. Instead, this interface implements
separate Bit Set and Bit Clear registers, allowing users
to individually work with volatile bits (such as interrupt
flags) without the risk of disturbing the values of other
bits. Setting the bit(s) in one of these registers sets or
clears the corresponding bit(s) in the base register.
In the PSP interface, Bit Set and Bit Clear registers are
located in different areas of the addressable memory
space from their corresponding “base” SFRs. The
address of the registers is always at a fixed offset from
their corresponding base register. For the 8-bit interface,
the offset is 100h (Set) or 180h (Clear). For the 16-bit
interface, the offset is 80H (Set) or C0 (Clear).
Symbolically, the names of the companion registers are
the names of the base registers, plus the suffix form
“-SET” (or “-SETH/SETL”) for Bit Set registers and
“-CLR” (“-CLRH/CLRL”) for Bit Clear registers.
Most SFRs have their own pair of Bit Set and Bit Clear
registers. However, these SFRs do not:
• MAC registers, including MI registers for PHY
access
• Read-only status registers (ERXHEAD, ETXSTAT,
ETXWIRE and ESTAT)
• All of the SRAM Buffer Pointers and data windows
(SFRs located at 7E80h to 7E9Fh in the 8-bit
interface, or 3F40h to 3F4Fh in the 16-bit
interface)
The Bit Set and Bit Clear registers for the 8-bit PSP
interface are listed in Table 3-4 and Table 3-5,
respectively. The registers for the 16-bit interface are
listed together in Table 3-6.
MAMXFLMAC Maximum Frame Length, High Byte (MAMXFL<15:8>)MAC Maximum Frame Length, Low Byte (MAMXFL<7:0>)
Legend:
— = unimplemented, read as ‘0’; q = unique MAC address or silicon revision nibble; r = reserved bit, do not modify; x = Reset value unknown. Reset values are shown in hexadecimal for each byte.
— = unimplemented, read as ‘0’; q = unique MAC address or silicon revision nibble; r = reserved bit, do not modify; x = Reset value unknown. Reset values are shown in hexadecimal for each byte.
The PHY registers provide configuration and control of
the PHY module, as well as status information about its
operation. These 16-bit registers are located in their
own memory space, outside of the main SFR space.
Unlike other SFRs, the PHY SFRs are not directly
accessible through the SPI or PSP interfaces. Instead,
access is accomplished through a special set of MAC
control registers that implement a Media Independent
Interface Management (MIIM) defined by IEEE 802.3;
these are the MICMD, MISTAT and MIREGADR
registers.
There are a total of 32 PHY addresses; however, only
10 locations implement user-accessible registers listed
in Table 3-8. Writes to unimplemented locations are
ignored and any attempts to read these locations return
FFFFh. Do not write to reserved PHY register locations
and ignore their content if read.
TABLE 3-8:PHY SPECIAL FUNCTION
REGISTER MAP
AddressNameAddressName
00PHCON110
01PHSTAT111PHCON2
02
03
04PHANA14
05PHANLPA15
06PHANE16
07
08
09
0A
0B
0C
0D
0E
0F
Reserved12Reserved
Reserved13—
—17Reserved
—18—
—19—
—1A—
—1BPHSTAT2
—1CReserved
—1DReserved
—1EReserved
—1FPHSTAT3
Reserved
Reserved
Reserved
Reserved
3.3.1READING PHY REGISTERS
When a PHY register is read, the entire 16 bits are
obtained.
To read from a PHY register:
1.Write the address of the PHY register to read
from into the MIREGADR register
(Register 3-1). Make sure to also set reserved
bit 8 of this register.
2.Set the MIIRD bit (MICMD<0>, Register 3-2).
The read operation begins and the BUSY bit
(MISTAT<0>, Register 3-3) is automatically set
by hardware.
3.Wait 25.6 s. Poll the BUSY (MISTAT<0>) bit to
be certain that the operation is complete. While
busy, the host controller should not start any
MIISCAN operations or write to the MIWR
register. When the MAC has obtained the register
contents, the BUSY bit will clear itself.
4.Clear the MIIRD (MICMD<0>) bit.
5.Read the desired data from the MIRD register.
For 8-bit interfaces, the order that these bytes
are read is unimportant.
3.3.2WRITING PHY REGISTERS
When a PHY register is written to, the entire 16 bits are
written at once; selective bit writes are not
implemented. If it is necessary to reprogram only select
bits in the register, the host microcontroller must first
read the PHY register, modify the resulting data and
then write the data back to the PHY register.
To write to a PHY register:
1.Write the address of the PHY register to write to
into the MIREGADR register. Make sure to also
set reserved bit 8 of this register.
2.Write the 16 bits of data into the MIWR register.
The low byte must be written first, followed by
the high byte.
3.Writing to the high byte of MIWR begins the
MIIM transaction and the BUSY (MISTAT<0>)
bit is automatically set by hardware.
The PHY register is written after the MIIM operation
completes, which takes 25.6 s. When the write operation has completed, the BUSY bit clears itself. The host
controller should not start any MIISCAN, MIWR or
MIIRD operations while the BUSY bit is set.
DS39935C-page 28 2010 Microchip Technology Inc.
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