ABRIDGED
DATA SHEET
MAX66240
EVALUATION KIT AVAILABLE
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
General Description
DeepCover® embedded security solutions cloak sensitive
data under multiple layers of advanced physical security
to provide the most secure key storage possible.
The DeepCover Secure Authenticator (MAX66240) is a
transponder IC that combines an ISO/IEC 15693 and ISO
18000-3 Mode 1-compatible RF front-end, a FIPS 180based SHA-256 engine, and 4096 bits of user EEPROM
in a single chip. A bidirectional security model enforces
two-way authentication between a host system and the
MAX66240. Each device has its own guaranteed unique
64-bit ROM ID that is factory programmed into the chip.
This ROM ID is used as a fundamental input parameter
for cryptographic operations and serves as an electronic
serial number within the application.
Features and Benefits
● Dedicated Hardware-Accelerated SHA Engine for
Generating SHA-256 MACs
● Strong Authentication with a High Bit Count UserProgrammable Secret and Input Challenge
● 4096 Bits of User EEPROM with User-Programmable
R/W Protection Options Including OTP/EPROM
Emulation Mode
● Unique Factory-Programmed 64-Bit Identification
Number
● ISO/IEC 15693: Up to 26kbps
● ±2kV HBM ESD Protection for All Pins
Applications
●
●
●
●
●
Access Control
Asset Tracking
Printer Cartridge Configuration and Monitoring
Medical Sensor Authentication and Calibration
System Intellectual Property Protection
Ordering Information appears at end of data sheet.
Typical Application Circuit
13.56MHz READER
MAGNETIC
COUPLING
TRANSMITTER
TX_OUT
RECEIVER
MAX66240
IC LOAD
RX_IN
SWITCHED
LOAD
ANTENNA
DeepCover is a registered trademark of Maxim Integrated
Products, Inc.
219-0042; Rev 5; 4/19
For related parts and recommended products to use with this part, refer
to www.maximintegrated.com/MAX66240.related.
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Absolute Maximum Ratings
Voltage Range on Any Pin Relative to GND.........-0.5V to +4.0V
Maximum RMS Current, AC1 to AC2..................................30mA
Maximum Incident Magnetic Field Strength
(ISO/IEC 7810-compliant antenna).................... 141.6dBµA/m
Operating Temperature Range............................ -40°C to +85°C
Junction Temperature.......................................................+150°C
Storage Temperature Range............................. -55°C to +125°C
Lead Temperature (soldering, 10s).................................. +300°C
Soldering Temperature (reflow)........................................+260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Package Thermal Characteristics (Note 1)
SO
Junction-to-Ambient Thermal Resistance (θJA).........136°C/W
Junction-to-Case Thermal Resistance (θJC)................38°C/W
TDFN
Junction-to-Ambient Thermal Resistance (θJA)...........60°C/W
Junction-to-Case Thermal Resistance (θJC)................30°C/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Electrical Characteristics
(TA = -40°C to +85°C, unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SHA-256 ENGINE
Computation Time
tCSHA
(Note 3)
2
ms
Programming Time for a 32-Bit
Page Block or Protection
tPROG
(Note 4)
10
ms
Write/Erase Cycling Endurance
NCY
TA = +85°C (Notes 5, 6)
100k
—
Data Retention
tDR
TA = +85°C (Notes 7, 8, 9)
10
Years
EEPROM
RF PORT
Carrier Frequency
fC
(Note 10)
Internal Tuning Cap
CTUN
f = 13.56MHz (Note 11)
Operating Field
HISO
(Note 10)
Activation Field Strength
Write/SHA Field Strength
13.553
13.560
MHz
5000
mA/m
27.5
150
HMIN_10
TA = +25°C, 10% modulation
(Notes 11, 12)
94
HMIN_30
TA = +25°C, 30% modulation
(Notes 11, 12)
104
HMIN_100
TA = +25°C, 100% modulation
(Notes 11, 12)
103.5
HWR
13.567
TA = +25°C (Notes 11, 12, 13)
pF
dBµA/m
113
dBµA/m
1.1
ms
RF Access in Progress Time
tRFAIP
10% Carrier Modulation Index
MI = (A - B)/(A + B)
CMI_10
(Notes 10, 11)
10
30
%
100% Carrier Modulation Index
MI = (A - B)/(A + B)
CMI_100
(Notes 10, 11)
95
100
%
10% Modulation Min Pulse
Width
www.maximintegrated.com
t1 MIN
Refer to ISO 15693-2 Section
7.1 (Notes 11, 14)
7.0
µs
Maxim Integrated │ 2
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Electrical Characteristics (continued)
(TA = -40°C to +85°C, unless otherwise noted.) (Note 2)
SYMBOL
CONDITIONS
10% Modulation Max Pulse
Width
PARAMETER
t1 MAX
Refer to ISO 15693-2 Section
7.1 (Note 11)
MIN
TYP
MAX
UNITS
9.44
µs
10% Modulation Min Low Time
t2 MIN
Refer to ISO 15693-2 Section
7.1 (Notes 11, 14)
10% Modulation Max Low Time
t2 MAX
Refer to ISO 15693-2 Section
7.1 (Note 11)
10% Modulation Min Rise Time
t3 MIN
Refer to ISO 15693-2 Section
7.1 (Note 11)
10% Modulation Max Rise Time
t3 MAX
Refer to ISO 15693-2 Section
7.1 (Notes 11, 14)
2.5
µs
100% Modulation Min Pulse
Width
t1 MIN
Refer to ISO 15693-2 Section
7.1 (Notes 11, 15)
6.5
µs
100% Modulation Min Pulse
Width
t1 MAX
Refer to ISO 15693-2 Section
7.1 (Note 11)
100% Modulation Max Pulse
Width
t2 MIN
Refer to ISO 15693-2 Section
7.1 (Notes 11, 15)
100% Modulation Max Low
Time
t2 MAX
Refer to ISO 15693-2 Section
7.1 (Note 11)
100% Modulation Min Rise
Time
t3 MIN
Refer to ISO 15693-2 Section
7.1 (Note 11)
100% Modulation Max Rise
Time
t3 MAX
Refer to ISO 15693-2 Section
7.1 (Notes 11, 15)
7.0
µs
9.44
0
µs
µs
9.44
6.5
µs
9.44
0
µs
µs
µs
3.0
µs
Note 2: Limits are 100% production tested at TA = +25°C or TA = +85°C. Limits over the operating temperature range and relevant
supply voltage range are guaranteed by design and characterization. Typical values are at +25°C.
Note 3: For commands where the tCSHA interval occurs see the applicable communication examples sections. For RF commands,
the interval begins after the EOF of a valid request frame. The interval ends once the device’s self-timed SHA-256 computation cycle is complete.
Note 4: For commands where the tPROG interval occurs see the applicable communication examples sections. For RF commands,
the interval begins after the EOF of a valid request frame. The interval ends once the device’s self-timed EEPROM write
cycle is complete.
Note 5: Write-cycle endurance is tested in compliance with JESD47G.
Note 6: Not 100% production tested; guaranteed by reliability qualification.
Note 7: Data retention is tested in compliance with JESD47G.
Note 8: Guaranteed by 100% production test at elevated temperature for a shorter time; equivalence of this production test to the
data sheet limit at operating temperature range is established by reliability testing.
Note 9: EEPROM writes can become nonfunctional after the data-retention time is exceeded. Long-term storage at elevated temperatures is not recommended.
Note 10: System requirement.
Note 11: Guaranteed by design and/or characterization only. Not production tested.
Note 12: Characterized in accordance with ISO/IEC 10373-7.
Note 13: Applies to Read/Write Scratchpad (writing), Write Memory, Compute and Read Page MAC, Set Protection, Authenticated
Write Memory RF Setup, Authenticated Write Memory RF Execute, Authenticated Set Protection RF Setup, and
Authenticated Set Protection RF Execute commands.
Note 14: Field strength between 350mA/m and 3A/m.
Note 15: Field strength between 350mA/m and 5A/m.
www.maximintegrated.com
Maxim Integrated │ 3
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Pin Configurations
TOP VIEW
D.N.C.
D.N.C.
1
AC2
2
AC1
3
D.N.C.
4
+
8 D.N.C.
10
D.N.C.
D.N.C.
D.N.C.
D.N.C.
9
8
7
6
7 D.N.C.
MAX66240
6 D.N.C.
MAX66240
5 D.N.C.
SO
7
+
8
1
D.N.C.
D.N.C.
D.N.C.
1
2
3
4
5
D.N.C. AC2 D.N.C. AC1 D.N.C.
AC2
2
AC1
3
TDFN
MAX66240
6
D.N.C.
D.N.C.
D.N.C.
5
4
BUMPED DIE
Pin Descriptions
PIN
SO/
BUMPED
DIE
TDFN
1, 4–8
1, 3, 5–10
D.N.C.
2
2
AC2
Antenna Connection
3
4
AC1
Antenna Connection
www.maximintegrated.com
NAME
FUNCTION
Do Not Connect
Maxim Integrated │ 4
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Detailed Description
The MAX66240 transponder combines an ISO 15693 RF
front-end, a SHA-256 engine, 4096 bits of user EEPROM
organized as 16 256-bit pages, protection control, status
memory, and a 64-bit ROM ID in a single chip. A 256-bit
scratchpad assists when installing a new secret or stores
the challenge when computing a page MAC.
It is common for a secure authentication IC to be attacked
using a variety of sophisticated die-level methods to
extract secure data, reverse device settings, etc., in an
effort to compromise a system security implementation.
To provide the highest affordable protection against this
inevitable malicious attack, the MAX66240 employs proprietary die-level physical techniques, circuits, and crypto
methods to protect sensitive data, control signals, and
control settings.
There are multiple programmable options for the 4Kb user
array including unrestricted read/write and four protection
modes: read protection, write protection, EPROM emulation mode, and authentication protection. Read protection
prevents user read-access to the memory, which effectively extends the secret into the protected memory. The
data remains accessible only for the SHA-256 engine.
Write protection prevents changes to the memory data.
EPROM emulation mode logically ANDs memory data
with incoming new data, which allows changing bits from
1 to 0, but not vice versa. By changing one bit at a time,
this mode could be used to create a nonvolatile, nonresettable counter. EPROM emulation mode requires that the
memory is not write protected. Authentication protection,
if activated, requires that the host prove itself as authentic
(i.e., knows the MAX66240 secret) to modify the memory
by supplying a correct MAC that is based on the device
secret, its ROM ID, memory data, and the new data to
be copied to EEPROM. If the authentication hurdle is
passed, the write protection and EPROM emulation mode
www.maximintegrated.com
protections still determine the effect of the write access.
Any protection, if activated, applies to individual memory
pages. As a factory default, none of the protections is
activated. Once authentication protection is activated, the
reader must authenticate itself for memory writes as well
as for additional changes to the memory protection.
In addition to its important use as a unique data value in
cryptographic SHA-256 computations, the device’s 64-bit
ROM ID can be used to electronically identify the object
to which the MAX66240 is associated. Applications of the
MAX66240 include, access control, asset tracking, printer
cartridge configuration and monitoring, medical sensor
authentication and calibration, and system intellectual
property protection.
Overview
The block diagram in Figure 1 shows the relationships
between the major control and memory sections of the
MAX66240. The device has six main data components:
16 256-bit pages of user EEPROM, a 256-bit secret, protection control/status memory, 512-bit SHA-256 engine,
64-bit ROM ID, and a 256-bit scratchpad.
Figure 2 shows the applicable commands and the
affected data fields. The network function commands
allow the reader to identify all transponders in its range
and to change their state, e.g., to select one for further
communication. The protocol required for these network
function commands is described in the Network Function
Commands section. The memory and control functions
fall into five categories: ISO 15693 generic commands,
secret installation, memory access, protection setting,
and MAC computation. The protocol for these commands is described in the Memory and Control Function
Commands section. All data is read and written least
significant bit (LSb) first, starting with the least significant
byte (LSB).
Maxim Integrated │ 5
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
MAX66240
DEVICE FUNCTION
CONTROL
VOLTAGE
REGULATOR
AC1
AC2
RF
FRONT
END
MEMORY
MANAGEMENT
MOD
SCRATCHPAD
SECRET
SHA-256
ENGINE
4kBIT EEPROM
ARRAY
DATA
fC
64 BIT UID ROM ID
ISO 15693
PROTOCOL
64 BIT UID
Figure 1. Block Diagram
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Maxim Integrated │ 6
ABRIDGED
DATA SHEET
MAX66240
COMMAND
TYPE:
NETWORK FUNCTION
COMMANDS
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
AVAILABLE
COMMANDS:
DATA FIELD
AFFECTED:
INVENTORY
STAY QUIET
SELECT
RESET TO READY
UID, AFI, DSFID
UID
UID
(N/A)
GET SYSTEM INFORMATION
WRITE MEMORY
UID, AFI, DSFID, CONSTANTS
MFGCODE, USER MEMORY, PROTECTION
SETTINGS
MFGCODE, USER MEMORY, PROTECTION
SETTINGS
SELECTED MEMORY BLOCK, PROTECTION
SETTINGS
SELECTED MEMORY BLOCKS, PROTECTION
SETTINGS
MFGCODE, PROTECTION SETTINGS
MFGCODE, PROTECTION SETTINGS,
PERSONALITY BYTES
MFGCODE, SCRATCHPAD
MFGCODE, SECRET AND LOCK STATUS,
SCRATCHPAD
MFGCODE, SECRET AND LOCK STATUS, USER
MEMORY, SCRATCHPAD, PROTECTION SETTING
MFGCODE, SECRET, ROM ID, USER MEMORY,
SCRATCHPAD
MFGCODE, USER MEMORY, PAGE BLOCK
NUMBER, SECRET, PROTECTION SETTINGS
MFGCODE, USER MEMORY
READ MEMORY
READ SINGLE BLOCK
READ MULTIPLE BLOCKS
SET PROTECTION
READ STATUS
READ/WRITE SCRATCHPAD
LOAD AND LOCK SECRET
MEMORY AND CONTROL
FUNCTION COMMANDS
COMPUTE AND LOCK SECRET
COMPUTE AND READ PAGE MAC
AUTHENTICATED WRITE
MEMORY RF SETUP
AUTHENTICATED WRITE
MEMORY RF EXECUTE
AUTHENTICATED SET
PROTECTION RF SETUP
AUTHENTICATED SET
PROTECTION RF EXECUTE
GET 1-WIRE ROM ID
WRITE AFI
LOCK AFI
WRITE DSFID
LOCK DSFID
MFGCODE, MEMORY PAGE NUMBER, SECRET,
PROTECTION SETTINGS
MFGCODE, PROTECTION SETTINGS
MFGCODE, ROM ID
AFI BYTE
AFI LOCK STATUS
DSFID BYTE
DSFID LOCK STATUS
Figure 2. Commands Overview
www.maximintegrated.com
Maxim Integrated │ 7
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Parasite Power
ROM ID
The MAX66240 receives all energy necessary for its
operation from the surrounding RF field, which needs to
have a minimum strength as specified in the Electrical
Characteristics table.
The read-only ROM ID is similar to the UID (Figure 4). The
first 8 bits are a family code, which is E0h. The next 28
bits are a unique serial number. The next 20 bits are fixed
at 2B000h. The last 8 bits are a cyclic redundancy check
(CRC) of the first 56 bits. The CRC is generated using the
polynomial X8 + X5 + X4 + 1 (Figure 5). Additional information about this CRC is available in Application Note
27: Understanding and Using Cyclic Redundancy Checks
with Maxim iButton® Products. The ROM ID is part of the
input data to the SHA-256 engine. It is read accessible
through the command Get 1-Wire ROM ID.
Unique Identification Number (UID)
Each MAX66240 contains a factory-programmed and
locked identification number that is 64 bits long (Figure 3).
The lower 28 bits are the serial number of the chip. The
upper 36 bits are fixed at E02B00800h. The code in bit
locations 49 to 56 identifies the chip manufacturer, according to ISO/IEC 7816-6/AM1. This code is 2Bh for Maxim.
The UID is read accessible through the Inventory and Get
System Information commands.
MSb
64
LSb
57
56
E0h
49
48
2Bh
45
44
37
0h
04h
36
29
28
00h
1
Serial Number
Figure 3. 64-Bit UID
LSb
MSb
8-bit
CRC Code
MSb
0h
2Bh
28-bit
Serial Number
00h
MSb
LSb
8-bit Family Code
(E0h)
LSb
MSb
LSb
Figure 4. 64-Bit ROM ID
POLYNOMIAL = X8 + X5 + X4 + 1
LSb
MSb
1ST
STAGE
X0
2ND
STAGE
X1
3RD
STAGE
X2
5TH
STAGE
4TH
STAGE
X3
X4
6TH
STAGE
X0
7TH
STAGE
X1
8TH
STAGE
X2
X3
INPUT DATA
Figure 5. 8-Bit CRC for the ROM ID
iButton is a registered trademark of Maxim Integrated Products,
Inc.
www.maximintegrated.com
Maxim Integrated │ 8
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Memory Resources
The memory of the MAX66240 consists of user
EEPROM, secret memory, an SRAM scratchpad, personality registers, ROM ID, and two ISO 15693-specific
bytes. Table 1 shows the size, access mode, and purpose
of the various memory areas. Brackets around an access
mode indicate possible restrictions, such as write protection or read protection.
The user memory is organized as 16 pages of 32 bytes
each (Figure 6). A page is divided into 8 page blocks of
32 bits each. With the MAX66240, the page protection
applies to individual memory pages. The user memory is
written in page blocks. If not read protected, the memory
can be read starting at any page block of any page. The
protocol allows reading multiple page blocks and pages up
to the end of the memory in a single read command flow.
The secret is either directly written (loaded) or computed.
This write access always encompasses the entire 32-byte
secret. To protect against transmission errors, the new
secret (loading) or a partial secret (computing) is first
written to the scratchpad from where it can be read for
verification. As the name implies, the secret memory is
not user readable. To protect a secret from changes, it
must be write protected (locked).
Page protection control is activated through the Write
Page Protection command. Besides write protection, read
protection and EPROM emulation mode, the MAX66240
supports authentication protection. If authentication protection is activated, changes to the page protection settings as well as writing to the protected user memory
require that the reader provide a valid MAC for the operation. Once a protection is activated, it cannot be reversed.
The protection settings as well as the personality registers
are read accessible through the Read Status command.
See the Memory and Control Function Commands section for command flow details.
Depending on the command, the ROM ID may be
required in the MAC computations. This makes the MAC
generated by a MAX66240 or written to the MAX66240
(if authentication protection is activated) device-specific,
even if the values of all other data elements are identical.
Instead of requiring the reader to derive the ROM ID from
the UID, the MAX66240 supports a special command to
read the ROM ID directly.
Note that the ISO 15693 standard commands Read
Single Block and Read Multiple Blocks do not address the
user memory by page number and page block number.
Instead, they use absolute block numbers counting from 0
to 127. Figure 7 shows how these absolute numbers map
to the user memory.
Table 1. Memory Resources
SIZE
(BYTES)
ACCESS MODE
User Memory
(EEPROM)
512
(Read), (Write),
Internal Read
Secret Memory
(EEPROM)
32
(Write), (Compute),
Internal Read
Scratchpad
(SRAM)
32
Read, Write,
Internal Read
Intermediate data storage when installing a secret; also used to
store the challenge for a MAC computation.
Personality Registers
4
Read,
Internal Read
Lock status indicator for the secret and read access to the device’s
manufacturer ID (factory preprogrammed parts).
ROM ID
8
Read,
Internal Read
Used for MAC computations.
Application Family
Identifier (AFI)
1
Read, (Write)
Can be used during the inventory phase to narrow the number
of transponders that participate in the discovery or anti-collision
process.
Data Storage Format
Identifier (DSFID)
1
Read, (Write)
User byte that can provide details on how the data in the user
memory is structured.
NAME
www.maximintegrated.com
PURPOSE
Application-specific data storage; also used for MAC computations.
Storage of the secret that is used for MAC computations.
Maxim Integrated │ 9
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
B0
B1
B2
B3
B0
B1
B2
B3
B0
B1
B2
B3
B0
B1
B2
B3
B0
B1
B2
B3
B0
B1
B2
B3
B0
B1
B2
B3
B0
B1
B2
B3
PG. BLOCK 7 PG. BLOCK 6 PG. BLOCK 5 PG. BLOCK 4 PG. BLOCK 3 PG. BLOCK 2 PG. BLOCK 1 PG. BLOCK 0
Page 0
Page 1
Page 2
Page 3
Page 4
Page 5
Page 6
Page 7
Page 8
Page 9
Page 10
Page 11
Page 12
Page 13
Page 14
Page 15
Figure 6. User Memory Map
PG. BLOCK 7 PG. BLOCK 6 PG. BLOCK 5 PG. BLOCK 4 PG. BLOCK 3 PG. BLOCK 2 PG. BLOCK 1 PG. BLOCK 0
Page 0
Block 7
Block 6
Block 5
Block 4
Block 3
Block 2
Block 1
Block 0
Page 1
Block 15
Block 14
Block 13
Block 12
Block 11
Block 10
Block 9
Block 8
Page 2
Block 23
Block 22
Block 21
Block 20
Block 19
Block 18
Block 17
Block 16
Page 3
Block 31
Block 30
Block 29
Block 28
Block 27
Block 26
Block 25
Block 24
Page 4
Block 39
Block 38
Block 37
Block 36
Block 35
Block 34
Block 33
Block 32
Page 5
Block 47
Block 46
Block 45
Block 44
Block 43
Block 42
Block 41
Block 40
Page 6
Block 55
Block 54
Block 53
Block 52
Block 51
Block 50
Block 49
Block 48
Page 7
Block 63
Block 62
Block 61
Block 60
Block 59
Block 58
Block 57
Block 56
Page 8
Block 71
Block 70
Block 69
Block 68
Block 67
Block 66
Block 65
Block 64
Page 9
Block 79
Block 78
Block 77
Block 76
Block 75
Block 74
Block 73
Block 72
Page 10
Block 87
Block 86
Block 85
Block 84
Block 83
Block 82
Block 81
Block 80
Page 11
Block 95
Block 94
Block 93
Block 92
Block 91
Block 90
Block 89
Block 88
Page 12
Block 103
Block 102
Block 101
Block 100
Block 99
Block 98
Block 97
Block 96
Page 13
Block 111
Block 110
Block 109
Block 108
Block 107
Block 106
Block 105
Block 104
Page 14
Block 119
Block 118
Block 117
Block 116
Block 115
Block 114
Block 113
Block 112
Page 15
Block 127
Block 126
Block 125
Block 124
Block 123
Block 122
Block 121
Block 120
Figure 7. User Memory Access Using Absolute Block Numbers
www.maximintegrated.com
Maxim Integrated │ 10
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
ISO/IEC 15693 Interface
(Figure 8). The last 2 bytes of an ISO 15693 frame are
an inverted 16-bit CRC of the preceding data generated
according to the CRC-16-CCITT polynomial X16 + X12 +
X5 + 1 (Figure 9). This CRC is transmitted with the LSB
first. For more details on the CRC-16-CCITT, refer to ISO
15693-3, Annex C. Frame information is modulated on
a 13.56MHz carrier. The subsequent paragraphs are a
concise description of the required modulation, coding,
and basic timing.
The communication between an HF reader and MAX66240
(transponder) is a master-transponder type transaction,
and is based on the exchange of data packets. The
reader initiates every transaction; only one side (reader
or transponder) transmits information at any time. Each
data packet begins with a start-of-frame (SOF) pattern
and ends with an end-of-frame (EOF) pattern. A data
packet delimited by an SOF and an EOF is called a frame
SOF
1 OR MORE DATA BYTES
CRC (LSB)
CRC (MSB)
EOF
TIME
Figure 8. ISO/IEC 15693 Frame Format
POLYNOMIAL = X16 + X12 + X5 + 1
MSb
1ST
STAGE
X0
2ND
STAGE
X1
3RD
STAGE
X2
4TH
STAGE
5TH
STAGE
6TH
STAGE
X4
X3
X5
7TH
STAGE
X6
8TH
STAGE
X7
LSb
9TH
STAGE
X8
10TH
STAGE
X9
11TH
STAGE
X10
12TH
STAGE
X11
13TH
STAGE
X12
14TH
STAGE
X13
15TH
STAGE
X14
16TH
STAGE
X15
X16
INPUT DATA
Figure 9. CRC-16-CCITT Generator
www.maximintegrated.com
Maxim Integrated │ 11
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Reader to Transponder Communication
the 75.52µs conveys the value of the 2 bits. A byte is
transmitted as a concatenation of four 2-bit transmissions,
with the least significant 2 bits of the byte being transmitted first. The transmission of the SOF pattern also takes
75.52µs. The SOF pattern has two modulation pauses.
The position of the second pause determines whether the
frame uses the “1 out of 256” or “1 out of 4” data coding
mode (Figure 13 and Figure 14, respectively). The transmission of the EOF pattern takes 37.76µs; the EOF is
the same for both coding modes and has one modulation
pause (Figure 15). For full details, refer to ISO 15693-2,
Sections 7 and 8.
The communication from reader to transponder uses
amplitude modulation (Figure 10); the modulation index
can be either in the range of 10% to 30% or 100% (ISO
15693-2, Section 7.1). The standard defines two pulseposition data coding modes. The “1 out of 256” data
coding mode transmits one 1 byte in 4.833ms, equivalent
to a data rate of 1655bps (Figure 11). The location of a
modulation pause during the 4.833ms conveys the value
of the byte. The “1 out of 4” data coding mode transmits
2 bits in 75.52µs, equivalent to a data rate of 26,484bps
(Figure 12). The location of a modulation pause during
CARRIER
AMPLITUDE
t1
t3
105%
A
95%
60%
MI = (A - B)/(A + B)
t2
5%
B
t
100% MODULATION
CARRIER
AMPLITUDE
t1
t2
t3
y
hf
A
B
hr
y
t
10% MODULATION
Figure 10. Reader to Transponder Modulation
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Maxim Integrated │ 12
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
PULSEMODULATED
CARRIER
~ 9.44µs
~ 18.88µs
0 1 2 3 4
.
.
.
.
.
.2 .
2
5
.
.
.
.
.
.
.
.
.
.
.
~ 4.833ms
.
.
.
.
.
.
.
.
. 2
5
2
2
5
3
2
5
4
2
5
5
Figure 11. Reader to Transponder “1 Out of 256” Data Coding
PULSE POSITION "00"
~ 9.44µs
~ 9.44µs
~ 75.52µs
PULSE POSITION "01" (1 = LSB)
~ 28.32µs
~ 9.44µs
~ 75.52µs
PULSE POSITION "10" (0 = LSB)
~ 47.20µs
~ 9.44µs
~ 75.52µs
PULSE POSITION "11"
~ 66.08µs
~ 9.44µs
~ 75.52µs
Figure 12. Reader to Transponder “1 Out of 4” Data Coding (Carrier Not Shown)
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Maxim Integrated │ 13
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
~ 9.44µs
~ 9.44µs
~ 37.76µs
~ 37.76µs
Figure 13. Reader to Transponder SOF for “1 Out of 256” Data Coding (Carrier Not Shown)
~ 9.44µs
~ 9.44µs
~ 37.76µs
~ 9.44µs
~ 37.76µs
Figure 14. Reader to Transponder SOF for “1 Out of 4” Data Coding (Carrier Not Shown)
~ 9.44µs
~ 9.44µs
~ 37.76µs
Figure 15. Reader to Transponder EOF (Identical for Both Coding Modes, Carrier Not Shown)
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Maxim Integrated │ 14
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Transponder to Reader Communication
The Subcarrier_flag bit in the request data frame specifies
the use of one or two subcarrier in the response frame.
For the one subcarrier case, the subcarrier frequency
is 423.75kHz. For the two subcarrier case, the subcarrier frequencies are 423.75kHz and 484.28kHz. The
Data_rate_flag bit in the request data frame specifies the
response frame data rate. Low data rate is approximately
6,600bps, and high data rate is approximately 26,500bps.
The data rate varies slightly depending on the use of one
or two subcarriers. The LSb is transmitted first.
In the single subcarrier high data rate case, one bit is
transmitted in 37.76µs. For a logic 0, the transponder
modulates for 16 cycles then does not modulate for 16
cycles, which is repeated 8 times. This is followed by 256
cycles of no modulation. For a logic 1, the transponder
does not modulate for 256 cycles. It then modulates for
16 cycles then does not modulate for 16 cycles, which
is repeated 8 times. An SOF or EOF is transmitted in
approximately 151µs. For an SOF, the transponder does
not modulate for 768 cycles. It then modulates for 16
cycles then does not modulate for 16 cycles, which is
repeated 24 times. This is followed by a logic 1. For an
EOF, the transponder sends a logic 0. It then modulates
for 16 cycles then does not modulate for 16 cycles, which
is repeated 24 times. This is followed by no modulation for
768 cycles. See Figure 16 and Figure 18 for more details.
For low data rate, multiply all cycle counts and times by 4.
In the two subcarrier low data rate case, one bit is transmitted in 37.46µs. For a logic 0, the transponder modulates
for 16 cycles then does not modulate for 16 cycles, which
is repeated 8 times. Next, the transponder modulates for
14 cycles then does not modulate for 14 cycles, which is
repeated 9 times. For a logic 1, the transponder modulates for 14 cycles then does not modulate for 14 cycles,
which is repeated 9 times. Next, the transponder modulates for 16 cycles then does not modulate for 16 cycles,
which is repeated 8 times. An SOF or EOF is transmitted
in approximately 149.8µs. For an SOF, the transponder
modulates for 14 cycles then does not modulate for 14
cycles, which is repeated 27 times. Next, the transponder
modulates for 16 cycles then does not modulate for 16
cycles, which is repeated 24 times. This is followed by a
logic 1. For an EOF, the transponder sends a logic 0. It
then modulates for 16 cycles then does not modulate for
16 cycles, which is repeated 24 times. Next, the transponder modulates for 14 cycles then does not modulate for
14 cycles, which is repeated 27 times. See Figure 17 and
Figure 19 for more details. For low data rate, multiply all
cycle counts and times by 4.
TRANSMITTING A ZERO
423.75kHz, ~ 18.88µs
~ 18.88µs
~ 37.76µs
TRANSMITTING A ONE
~ 18.88µs
423.75kHz, ~ 18.88µs
~ 37.76µs
Figure 16. Transponder to Reader Coding, Single Subcarrier Bit Coding (High Data-Rate Timing)
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Maxim Integrated │ 15
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
423.75kHz, ~ 18.88µs
484.28kHz, ~ 18.58µs
~ 37.46µs
TRANSMITTING A ZERO
484.28kHz, ~ 18.58µs
423.75kHz, ~ 18.88µs
~ 37.46µs
TRANSMITTING A ONE
Figure 17. Transponder to Reader Coding, Two Subcarriers Bit Coding (High Data-Rate Timing)
423.75kHz
~ 56.64µs
423.75kHz
~ 56.64µs
~ 37.76µs
Figure 18. Transponder to Reader SOF, One Subcarrier (High Data Rate)
484.28kHz
~ 55.75µs
423.75kHz
~ 56.64µs
423.75kHz
484.28kHz
~ 37.46µs
Figure 19. Transponder to Reader SOF, Two Subcarriers (High Data Rate)
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Maxim Integrated │ 16
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
ISO 15693 Transponder States
and State Transitions
ISO 15693 defines four transponder states and three
address modes. The states are power-off, ready, quiet,
and selected. The address modes are nonaddressed,
addressed, and select. The addressed mode requires that
the reader include the transponder’s UID in the request.
Figure 20 shows how the Reset to Ready, Stay Quiet, and
Select commands respond when changing the transponder’s state. Table 2 shows how other commands respond
depending on address mode and the transponder’s state.
Note that Stay Quiet never generates a response. For full
details, refer to ISO 15693-2, Section 7.
Power-Off State
This state applies if the transponder is outside the reader’s RF field. A transponder transitions to the power-off
state when leaving the power-delivering RF field. When
entering the RF field, the transponder automatically transitions to the ready state.
Ready State
In this state, a transponder has enough power to perform
any of its functions. The purpose of the ready state is to
have the transponder population ready to process the
inventory command as well as other commands sent in
the addressed or nonaddressed mode. A transponder
can exit the ready state and transition to the quiet or the
selected state upon receiving the Stay Quiet or Select
command sent in addressed mode.
Quiet State
In this state, a transponder has enough power to perform
any of its functions. The purpose of the quiet state is to
silence transponders with which the reader does not want
to communicate. Only commands sent with the addressed
mode are processed. This way the reader can use the
nonaddressed mode for communication with remaining
transponders in the ready state. A transponder can exit the
quiet state and transition to the ready state upon receiving
the Reset to Ready command in addressed or nonaddressed mode. It can also transition to the selected state
upon receiving Select commands sent in addressed mode.
Selected State
In this state, a transponder has enough power to perform
any of its functions. The purpose of the selected state is
to isolate the transponder with which the reader wants
to communicate. Commands are processed regardless
of the address mode in which they are sent, including
the Inventory command. With multiple transponders in
the RF field, the reader can put one transponder in the
selected state, leaving all others in the ready state. For a
transponder in the selected state, the reader can use the
selected mode, which keeps the request data packets as
short as with the nonaddressed mode. A new transponder
entering the RF field will not disturb communication since
it powers up in the ready state. A transponder can exit
the selected state and transition to the ready state upon
receiving the Reset to Ready command sent in nonaddressed or addressed mode. It can also transition to the
quiet state upon receiving the Stay Quiet command sent
in the addressed mode. A transponder also transitions
from selected to ready upon receiving a Select command
if the UID in the request is different from the transponder’s
own UID. In this case, the reader’s intention is to transition another transponder with the matching UID to the
selected state. If the transponder already in the selected
state does not recognize the command, e.g., due to a bit
error, two transponders could be in the selected state. To
prevent this from happening, the reader should use the
Reset to Ready or the Stay Quiet command to transition
a transponder out of the selected state.
Table 2. Command Response vs. Transponder State and Address Mode Combinations
ADDRESS MODES
TRANSPONDER
STATES
NONADDRESSED MODE
(Address_flag = 0;
Select_flag = 0)
ADDRESSED MODE
(Address_flag = 1;
Select_flag = 0)
SELECT MODE
(Address_flag = 0;
Select_flag = 1)
Power-Off
(Inactive)
(Inactive)
(Inactive)
Ready
Respond
Respond
Do not respond
Quiet
Do not respond
Respond
Do not respond
Selected
Respond
Respond
Respond
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DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
RESPONSE LEGEND:
ADDRESS MODE LEGEND:
RESPONSE TO RESET TO READY
RESPONSE TO SELECT
NO RESPONSE
[N] NONADDRESSED MODE
[A] ADDRESSED MODE
[S] SELECT MODE
POWER-OFF
OUT OF FIELD
IN FIELD
NOTE 1
OUT OF FIELD
OUT OF FIELD
READY
RESET TO READY
[N,A], MATCHING UID
RESET TO READY
[S]
SELECT [A],
MATCHING UID
STAY QUIET [A],
MATCHING UID
SELECT [A],
NONMATCHING UID
STAY QUIET [A], MATCHING UID
QUIET
SELECTED
SELECT [A], MATCHING UID
NOTE 2
NOTE 3
NOTE 1: THE TRANSPONDER PROCESSES THE INVENTORY COMMAND, AND PROCESSES OTHER COMMANDS IN NONADDRESSED
MODE OR ADDRESSED MODE WITH MATCHING UID.
NOTE 2: THE TRANSPONDER DOES NOT PROCESS THE INVENTORY COMMAND, AND PROCESSES OTHER COMMANDS IN
ADDRESSED MODE WITH MATCHING UID.
NOTE 3: THE TRANSPONDER PROCESSES THE INVENTORY COMMAND, AND PROCESSES OTHER COMMANDS IN NONADDRESSED
MODE, ADDRESSED MODE WITH MATCHING UID, OR SELECT MODE.
Figure 20. ISO 15693 State Transition Diagram
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ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Wait Times
ISO 15693 defines several standard wait times. For full
details, refer to ISO 15693-2, Section 9.
The wait time from request frame EOF to response
frame SOF is t1. t1 min is 318.6µs (4320 cycles), t1 nom
is 320.9µs (4352 cycles), and t1 max is 323.3µs (4384
cycles). Commands that perform MAC calculations or
write memory will extend t1 by a command specific combination of tRFAIP, tCSHA, and tPROG. If a 100% modulation
pulse is detected during t1, the transponder must restart
its t1 counter.
The 10% modulation ignore time after a request frame
EOF is received is tMIT. tMIT min is 323.3µs (4384 cycles)
+ tNRT, where tNRT is the nominal response frame length.
Network Function Command Errors
Various error conditions can occur. If an error occurs, and
the request is sent in addressed mode with matching UID
or in select mode with the transponder in the Selected
state, the transponder will transmit an error response. In
any other mode/state combination, an error will result in
no response. In case of an error response, the response
begins with response flags of 01h, followed by a singlebyte error code. Table 5 shows a matrix of commands,
errors, and error codes.
Table 5. Network Function Command
Error Code Matrix
The wait time between a response frame and a subsequent request frame is t2. t2 min is 309.2µs (4192 cycles).
Invalid Request Packet
Option Flag Set
The wait time between slot EOFs in an Inventory command where Nb_slots_flag is t3. For 100% modulation,
t3MIN is 323.3µs (4384 cycles) + tSOF, where tSOF is the
time requires to transmit a request frame SOF. For 10%
modulation, t3 min is 323.3µs (4384 cycles) + tNRT +
t2MIN, where tNRT is the nominal response frame length.
02h
03h
Reset to Ready
ü
ü
Select
ü
ü
ERROR EXPLANATION
Network Function Commands
The ISO 15693 standard defines four network function
commands: Inventory, Stay Quiet, Select, and Reset to
Ready. Their purpose is to identify the UIDs of all transponders in the field (to Inventory) and to manage access
to these transponders. Figure 20 shows how the network
function commands are used to transition a transponder
from one state to another.
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ERROR CODE
FAILING COMMAND
Maxim Integrated │ 20
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DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Detailed Command Descriptions
Inventory
This command allows the reader to learn the UIDs and
DSFIDs of all transponders in its RF field in an iterative
process.
The AFI_flag determines if the AFI byte must be included
in the request frame. The AFI byte is compared to the
transponders AFI. The parameter byte determines the
length of the mask. The LSb of the mask aligns with the
LSb of the transponder’s UID. The mask is compared to
the transponder’s UID. The Nb_slots_flag determines if
a slot counter is concantenated with the mask for comparison to the transponder’s UID. The slot counter starts
at 0000b after the Inventory request frame is transmitted,
and increments during the course of the Inventory command with every subsequent EOF sent by the reader. The
AFI byte (if used) must match the transponder’s AFI or be
00h, and the mask concatenated with the slot counter (if
used) must match the transponder’s UID for a response to
be generated. This allows the reader to select transponders to respond to the Inventory command. The processing of an Inventory command ends if the transponder
receives an SOF of a new request frame.
If a transponder meets all conditions to respond, it transmits a response frame. If multiple transponders meet the
conditions, the response frames collide and may not be
readable. The reader must eliminate the collision.
To identify all transponders in the RF field, the reader
could begin with a mask length of 0 and activate the
slot counter (Nb_slots_flag = 0). By using this method
and going through all 16 slots, the reader has a chance
to receive clean responses (i.e., the transponder is
identified) as well as colliding responses. To prevent a
transponder that has been identified from further participating in the collision management sequence, the reader
transitions it to the quiet state. Next, the reader issues
another Inventory command where the slot number that
previously generated a collision is now used as a 4-bit
mask, and runs again through all 16 slots. If a collision
is found, another Inventory command is issued, this time
with a mask that is extended at the higher bits by the slot
counter value that produced the collision. This process
is repeated until all transponders are identified. For a full
description of the Inventory command processing by the
transponder and the timing specifications, refer to ISO
15693 Part 3, Sections 8 to 9.
Inventory
Command Code
01h
Parameter Byte
Mask Length (Table 6)
Conditions, Restrictions
The command is ignored unless the transponder is in the Ready or Selected state.
Protocol Variations
•
•
•
•
•
•
•
•
Other Notes
For the setting of the request flags (RQF), see Table 4.
The mask pattern is transmitted only if the mask length is ≠ 0.
The AFI is transmitted only if the AFI_flag bit in the request flags is set to 1.
Error Conditions
(Error Response)
An error will result in no response.
t1 (Request Frame to
Response Frame Delay)
318.6µs to 323.3µs
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Nb_slot_flag = 0, AFI_flag = 0, mask length = 0
Nb_slot_flag = 0, AFI_flag = 0, mask length ≠ 0
Nb_slot_flag = 0, AFI_flag = 1, mask length = 0
Nb_slot_flag = 0, AFI_flag = 1, mask length ≠ 0
Nb_slot_flag = 1, AFI_flag = 0, mask length = 0
Nb_slot_flag = 1, AFI_flag = 0, mask length ≠ 0
Nb_slot_flag = 1, AFI_flag = 1, mask length = 0
Nb_slot_flag = 1, AFI_flag = 1, mask length ≠ 0
Maxim Integrated │ 21
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Table 6. Parameter Byte Bitmap
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
MLEN
Bits [7:0]: Mask Length (MLEN). These bits specify the length of the mask. The mask (MASK) is transmitted only if
MLEN is ≠ 0. The maximum mask length is 60 (3Ch, if Nb_slots_flag = 0) or 64 (40h, if Nb_slots_flag = 1).
Stay Quiet
This command addresses an individual transponder and transitions it to the Quiet state. The transponder does not send
a response.
Stay Quiet
Command Code
02h
Parameter Byte
N/A
Conditions, Restrictions
To transition to the Quiet state, the request must be sent in addressed mode with matching UID.
Protocol Variations
None
Other Notes
For the setting of the request flags (RQF), see Table 3.
Error Conditions
(Error Response)
An error will result in no response.
t1 (Request Frame to
Response Frame Delay)
None
Select
This command addresses an individual transponder and transitions it to the Selected state. The transponder transitioning
to the Selected state sends a response. If there was a transponder with a different UID in the Selected state, then that
transponder transitions to the Ready state without sending a response.
Select
Command Code
25h
Parameter Byte
N/A
Conditions, Restrictions
To transition to the Selected state, the request must be sent in addressed mode with matching UID.
Protocol Variations
None
Other Notes
For the setting of the request flags (RQF), see Table 3.
Error Conditions
(Error Response)
•
•
t1 (Request Frame to
Response Frame Delay)
318.6µs to 323.3µs
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Request data format error (response error code = 02h)
The Option_flag is set (response error code = 03h)
Maxim Integrated │ 22
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MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Reset to Ready
This command addresses an individual transponder and transitions it to the Ready state. The transponder transitioning
to the Ready state sends a response.
Reset to Ready
Command Code
26h
Parameter Byte
N/A
Conditions, Restrictions
To transition from the Quiet state to the Ready state, the request must be sent in nonaddressed mode
or in addressed mode with matching UID. To transition from the Selected state to the Ready state, the
request must be sent in select mode.
Protocol Variations
•
If the transponder is in the Selected state, and the request is sent in addressed mode with
nonmatching UID, the transponder transitions to the Ready state, but will not respond.
Other Notes
For the setting of the request flags (RQF), see Table 3.
Error Conditions
(Error Response)
•
•
t1 (Request Frame to
Response Frame Delay)
318.6µs to 323.3µs
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Request data format error (response error code = 02h)
The Option_flag is set (response error code = 03h)
Maxim Integrated │ 23
ABRIDGED
DATA SHEET
MAX66240
DeepCover Secure Authenticator with
ISO 15693, SHA-256, and 4Kb User EEPROM
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX66240ESA+
-40°C to +85°C
8 SO
MAX66240ESA+T
-40°C to +85°C
8 SO
(2.5k pcs)
MAX66240ETB+
-40°C to +85°C
10 TDFN
MAX66240ETB+T
-40°C to +85°C
10 TDFN
(2.5k pcs)
MAX66240E/D+T
-40°C to +85°C
AU bumped,
tested, dice
(2.5k pieces)
MAX66240E/W+†
-40°C to +85°C
AU bumped,
tested, diced
wafer
MAX66240/W+†
-40°C to +85°C
Tested wafer
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
†Contact factory for further details.
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
OUTLINE NO.
LAND PATTERN NO.
8 SO (150 mils)
S8+2
21-0041
90-0096
10 TDFN (3mm x 4mm)
T1034N+1
21-0268
90-0247
Bumped die
—
21-100050
—
Wafer
—
—
—
Errata
ISO 15693-3 Section 9.1 specifies that if the VICC detects a carrier modulation during time t1, it shall reset its t1 timer
and wait for a further time t1 before starting to transmit its response to a VCD request or to switch to the next slot when
in an inventory process. The MAX66240 is not compliant with this specification.
ISO15693-3 Section 9.4.2 specifies that during an inventory process, when the VCD has received no VICC response,
it shall wait a time t3 before sending a subsequent EOF to switch to the next slot. If the VCD sends a 100% modulated
EOF, the minimum value of t3 is 4384/fc (323.3µs) + tsof. The MAX66240 is not compliant with this specification. The
MAX66240 requires a minimum t3 = 4384/fc (323.3µs) + tnrt + t2min, where tsof is the time duration for a VICC to transmit
an SOF to the VCD, and tnrt is the nominal response time of a VICC. tnrt and tsof are dependent on the VICC-to-VCD
data rate and subcarrier modulation mode.
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Maxim Integrated │ 57
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