MICROCHIP HCS201

HCS201
KEELOQ® Code Hopping Encoder
FEATURES
DESCRIPTION
Security
The HCS201 from Microchip Technology Inc. is a code
hopping encoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS201 utilizes the KEELOQ
code hopping technology, incorporating high security, a
small package outline and low cost. The HCS201 is a
perfect solution for unidirectional remote keyless entry
systems and access control systems.
•
•
•
•
•
•
Programmable 28-bit serial number
Programmable 64-bit encryption key
Each transmission is unique
66-bit transmission code length
32-bit hopping code
34-bit fixed code (28-bit serial number,
4-bit button code, 2-bit status)
• Encryption keys are read protected
PACKAGE TYPES
PDIP, SOIC
S0
1
• 3.5V-13V operation
(2.0V min. using the Step up feature)
• Three button inputs
• 7 functions available
• Selectable baud rate
• Automatic code word completion
• Battery low signal transmitted to receiver
• Non-volatile synchronization data
S1
2
S2
3
VDDB
4
HCS201
Operating
 2001 Microchip Technology Inc.
STEP
DATA
5
VSS
Step Up
Controller
VDD
Controller
RESET circuit
EEPROM
STEP
Power
latching
and
switching
Oscillator
DATA
• The HCS201 is ideal for Remote Keyless Entry
(RKE) applications. These applications include:
• Automotive RKE systems
• Automotive alarm systems
• Automotive immobilizers
• Gate and garage door openers
• Identity tokens
• Burglar alarm systems
7
6
VDDB
Simple programming interface
On-chip EEPROM
On-chip oscillator and timing components
Button inputs have internal pull-down resistors
Minimum component count
Synchronous Transmission mode
Built-in step up regulator
Typical Applications
VDD
HCS201 BLOCK DIAGRAM
Other
•
•
•
•
•
•
•
8
Encoder
32-bit shift register
VSS
Button input port
VDD
S2 S1 S0
The HCS201 combines a 32-bit hopping code,
generated by a nonlinear encryption algorithm, with a
28-bit serial number and 6 information bits to create a
66-bit code word. The code word length eliminates the
threat of code scanning and the code hopping mechanism makes each transmission unique, thus rendering
code capture and resend schemes useless.
DS41098C-page 1
HCS201
The crypt key, serial number and configuration data are
stored in an EEPROM array which is not accessible via
any external connection. The EEPROM data is programmable but read-protected. The data can be verified only after an automatic erase and programming
operation. This protects against attempts to gain
access to keys or manipulate synchronization values.
The HCS201 provides an easy-to-use serial interface
for programming the necessary keys, system parameters and configuration data.
1.0
SYSTEM OVERVIEW
Key Terms
The following is a list of key terms used throughout this
data sheet. For additional information on KEELOQ and
Code Hopping, refer to Technical Brief 3 (TB003).
• RKE - Remote Keyless Entry
• Button Status - Indicates what button input(s)
activated the transmission. Encompasses the 4
button status bits S3, S2, S1 and S0 (Figure 4-2).
• Code Hopping - A method by which a code,
viewed externally to the system, appears to
change unpredictably each time it is transmitted.
• Code word - A block of data that is repeatedly
transmitted upon button activation (Figure 4-1).
• Transmission - A data stream consisting of
repeating code words (Figure 8-1).
• Crypt key - A unique and secret 64-bit number
used to encrypt and decrypt data. In a symmetrical block cipher such as the KEELOQ algorithm,
the encryption and decryption keys are equal and
will therefore be referred to generally as the crypt
key.
• Encoder - A device that generates and encodes
data.
• Encryption Algorithm - A recipe whereby data is
scrambled using a crypt key. The data can only be
interpreted by the respective decryption algorithm
using the same crypt key.
• Decoder - A device that decodes data received
from an encoder.
• Decryption algorithm - A recipe whereby data
scrambled by an encryption algorithm can be
unscrambled using the same crypt key.
• Learn – Learning involves the receiver calculating
the transmitter’s appropriate crypt key, decrypting
the received hopping code and storing the serial
number, synchronization counter value and crypt
key in EEPROM. The KEELOQ product family facilitates several learning strategies to be implemented on the decoder. The following are
examples of what can be done.
- Simple Learning
The receiver uses a fixed crypt key, common
to all components of all systems by the same
manufacturer, to decrypt the received code
word’s encrypted portion.
- Normal Learning
The receiver uses information transmitted
during normal operation to derive the crypt
key and decrypt the received code word’s
encrypted portion.
- Secure Learn
The transmitter is activated through a special
button combination to transmit a stored 60-bit
seed value used to generate the transmitter’s
crypt key. The receiver uses this seed value
to derive the same crypt key and decrypt the
received code word’s encrypted portion.
• Manufacturer’s code – A unique and secret 64bit number used to generate unique encoder crypt
keys. Each encoder is programmed with a crypt
key that is a function of the manufacturer’s code.
Each decoder is programmed with the manufacturer code itself.
The HCS201 code hopping encoder is designed specifically for keyless entry systems; primarily vehicles and
home garage door openers. The encoder portion of a
keyless entry system is integrated into a transmitter,
carried by the user and operated to gain access to a
vehicle or restricted area. The HCS201 is meant to be
a cost-effective yet secure solution to such systems,
requiring very few external components (Figure 2-1).
Most low-end keyless entry transmitters are given a
fixed identification code that is transmitted every time a
button is pushed. The number of unique identification
codes in a low-end system is usually a relatively small
number. These shortcomings provide an opportunity
for a sophisticated thief to create a device that ‘grabs’
a transmission and retransmits it later, or a device that
quickly ‘scans’ all possible identification codes until the
correct one is found.
The HCS201, on the other hand, employs the KEELOQ
code hopping technology coupled with a transmission
length of 66 bits to virtually eliminate the use of code
‘grabbing’ or code ‘scanning’. The high security level of
the HCS201 is based on the patented KEELOQ technology. A block cipher based on a block length of 32 bits
and a key length of 64 bits is used. The algorithm
obscures the information in such a way that even if the
transmission information (before coding) differs by only
one bit from that of the previous transmission, the next
DS41098C-page 2
 2001 Microchip Technology Inc.
HCS201
coded transmission will be completely different. Statistically, if only one bit in the 32-bit string of information
changes, greater than 50 percent of the coded transmission bits will change.
As indicated in the block diagram on page one, the
HCS201 has a small EEPROM array which must be
loaded with several parameters before use; most often
programmed by the manufacturer at the time of production. The most important of these are:
The crypt key generation typically inputs the transmitter
serial number and 64-bit manufacturer’s code into the
key generation algorithm (Figure 1-2). The manufacturer’s code is chosen by the system manufacturer and
must be carefully controlled as it is a pivotal part of the
overall system security.
• A 28-bit serial number, typically unique for every
encoder
• A crypt key
• An initial 16-bit synchronization value
• A 16-bit configuration value
FIGURE 1-1:
CREATION AND STORAGE OF CRYPT KEY DURING PRODUCTION
Production
Programmer
HCS201
Transmitter
Serial Number
EEPROM Array
Serial Number
Crypt Key
Sync Counter
Manufacturer’s
Code
Key
Generation
Algorithm
The 16-bit synchronization counter is the basis behind
the transmitted code word changing for each transmission; it increments each time a button is pressed. Due
to the code hopping algorithm’s complexity, each increment of the synchronization value results in greater
than 50% of the bits changing in the transmitted code
word.
Figure 1-2 shows how the key values in EEPROM are
used in the encoder. Once the encoder detects a button
press, it reads the button inputs and updates the synchronization counter. The synchronization counter and
crypt key are input to the encryption algorithm and the
output is 32 bits of encrypted information. This data will
change with every button press, its value appearing
externally to ‘randomly hop around’, hence it is referred
to as the hopping portion of the code word. The 32-bit
hopping code is combined with the button information
and serial number to form the code word transmitted to
the receiver. The code word format is explained in
greater detail in Section 4.0.
Crypt
Key
.
.
.
A transmitter must first be ‘learned’ by the receiver
before its use is allowed in the system. Learning
includes calculating the transmitter’s appropriate crypt
key, decrypting the received hopping code and storing
the serial number, synchronization counter value and
crypt key in EEPROM.
In normal operation, each received message of valid
format is evaluated. The serial number is used to determine if it is from a learned transmitter. If from a learned
transmitter, the message is decrypted and the synchronization counter is verified. Finally, the button status is
checked to see what operation is requested. Figure 1-3
shows the relationship between some of the values
stored by the receiver and the values received from
the transmitter.
A receiver may use any type of controller as a decoder,
but it is typically a microcontroller with compatible firmware that allows the decoder to operate in conjunction
with an HCS201 based transmitter. Section 7.0
provides detail on integrating the HCS201 into a system.
 2001 Microchip Technology Inc.
DS41098C-page 3
HCS201
FIGURE 1-2:
BUILDING THE TRANSMITTED CODE WORD (ENCODER)
EEPROM Array
KEELOQ
Encryption
Algorithm
Crypt Key
Sync Counter
Serial Number
Button Press
Information
Serial Number
32 Bits
Encrypted Data
Transmitted Information
FIGURE 1-3:
BASIC OPERATION OF RECEIVER (DECODER)
1 Received Information
EEPROM Array
Button Press
Information
Serial Number
2
32 Bits of
Encrypted Data
Manufacturer Code
Check for
Match
Serial Number
Sync Counter
Crypt Key
3
KEELOQ
Decryption
Algorithm
Decrypted
Synchronization
Counter
4
Check for
Match
Perform Function
5 Indicated by
button press
NOTE: Circled numbers indicate the order of execution.
DS41098C-page 4
 2001 Microchip Technology Inc.
HCS201
2.0
ENCODER OPERATION
TABLE 2-1:
As shown in the typical application circuits (Figure 2-1),
the HCS201 is a simple device to use. It requires only
the addition of buttons and RF circuitry for use as the
transmitter in your security application. A description of
each pin is given in Table 2-1.
FIGURE 2-1:
TYPICAL CIRCUITS
VDD
B0
S0
VDD
B1
S1
STEP
S2
DATA
Tx out
VSS
VDDB
Two button remote control
VDD
B3 B2 B1 B0
S0
VDD
S1
STEP
S2
DATA
VDDB
Tx out
VSS
Four button remote control
VDD
Pin
Pin
Name Number
PIN DESCRIPTIONS
Pin Description
S0
1
Switch input 0
S1
2
Switch input 1
S2
3
Switch input 2 / Clock pin for
Programming mode
VDDB
4
Battery input pin, supplies power
to the step up control circuitry
VSS
5
Ground reference connection
DATA
6
Pulse Width Modulation (PWM)
output pin / Data pin for
Programming mode
STEP
7
Step up regulator switch control
VDD
8
Positive supply voltage
The HCS201 will wake-up upon detecting a button
press and delay approximately 10 ms for button
debounce (Figure 2-2). The synchronization counter,
discrimination value and button information will be
encrypted to form the hopping code. The hopping code
portion will change every transmission, even if the
same button is pushed again. A code word that has
been transmitted will not repeat for more than 64K
transmissions. This provides more than 18 years of use
before a code is repeated; based on 10 operations per
day. Overflow information sent from the encoder can be
used to extend the number of unique transmissions to
more than 192K.
If in the transmit process it is detected that a new button(s) has been pressed, a RESET will immediately
occur and the current code word will not be completed.
Please note that buttons removed will not have any
effect on the code word unless no buttons remain
pressed; in which case the code word will be completed
and the power-down will occur.
L
D
S0
VDD
S1
STEP
S2
DATA
R
VDDB
Q
C
Tx out
VSS
2.0-6.0V
Three button remote control with Step up regulator
External components sample values:
R = 5.1 KΩ
L = 390 uH
C = 1.0 uF
D = ZHCS400CT (40V 0.4A Zetex)
Q = 2N3904
(see Section 5.6 for a description of the Step Up circuit)
Note:
Up to 7 functions can be implemented by pressing
more than one button simultaneously or by using a
suitable diode array.
 2001 Microchip Technology Inc.
DS41098C-page 5
HCS201
FIGURE 2-2:
ENCODER OPERATION
3.0
EEPROM MEMORY
ORGANIZATION
Power-Up
(A button has been pressed)
RESET and Debounce Delay
(10 ms)
Sample Inputs
The HCS201 contains 192 bits (12 x 16-bit words) of
EEPROM memory (Table 3-1). This EEPROM array is
used to store the encryption key information, synchronization value, etc. Further descriptions of the memory
array is given in the following sections.
TABLE 3-1:
Update Sync Info
Encrypt With
Crypt Key
WORD
ADDRESS
MNEMONIC
0
KEY_0
64-bit encryption key
(word 0)
1
KEY_1
64-bit encryption key
(word 1)
2
KEY_2
64-bit encryption key
(word 2)
3
KEY_3
64-bit encryption key
(word 3)
4
SYNC
16-bit synchronization
value
Load Transmit Register
Transmit
Yes
Buttons
Added
?
No
All
Buttons
Released
?
EEPROM MEMORY MAP
No
5
Yes
Complete Code
Word Transmission
Stop
3.1
DESCRIPTION
RESERVED Set to 0000H
6
SER_0
Device Serial Number
(word 0)
7
SER_1
Device Serial Number
(word 1)
8
SEED_0
Seed Value (word 0)
9
SEED_1
Seed Value (word 1)
10
DISC
Discrimination Word
11
CONFIG
Config Word
KEY_0 - KEY_3 (64-Bit Crypt Key)
The 64-bit crypt key is used to create the encrypted
message transmitted to the receiver. This key is calculated and programmed during production using a key
generation algorithm. The key generation algorithm
may be different from the KEELOQ algorithm. Inputs to
the key generation algorithm are typically the transmitter’s serial number and the 64-bit manufacturer’s code.
While the key generation algorithm supplied from
Microchip is the typical method used, a user may elect
to create their own method of key generation. This may
be done providing that the decoder is programmed with
the same means of creating the key for
decryption purposes.
3.2
SYNC (Synchronization Counter)
This is the 16-bit synchronization value that is used to
create the hopping code for transmission. This value
will increment after every transmission.
DS41098C-page 6
 2001 Microchip Technology Inc.
HCS201
3.3
Reserved
Must be initialized to 0000H.
serial number then it may merely be compared to the
respective bits of the received serial number; saving
EEPROM space.
3.4
3.7
SER_0, SER_1
(Encoder Serial Number)
SER_0 and SER_1 are the lower and upper words of
the device serial number, respectively. Although there
are 32 bits allocated for the serial number, only the
lower order 28 bits are transmitted. The serial number
is meant to be unique for every transmitter.
3.5
SEED_0, SEED_1 (Seed Word)
The 2-word (32-bit) seed code will be transmitted when
all three buttons are pressed at the same time (see
Figure 4-2). This allows the system designer to implement the secure learn feature or use this fixed code
word as part of a different key generation/tracking process.
TABLE 3-2:
Bit Number
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
3.6
The Configuration Word is a 16-bit word stored in
EEPROM array that is used by the device to store information used during the encryption process, as well as
the status of option configurations. Further explanations of each of the bits are described in the following
sections.
TABLE 3-3:
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Bit Description
DISC
(Discrimination Word)
The discrimination value aids the post-decryption
check on the decoder end. It may be any value, but in
a typical system it will be programmed as the 12 Least
Significant bits of the serial number. Values other than
this must be separately stored by the receiver when a
transmitter is learned. The discrimination bits are part
of the information that form the encrypted portion of
the transmission (Figure 4-2). After the receiver has
decrypted a transmission, the discrimination bits are
checked against the receiver’s stored value to verify
that the decryption process was valid. If the discrimination value was programmed as the 12 LSb’s of the
 2001 Microchip Technology Inc.
CONFIGURATION WORD
Bit Number
DISCRIMINATION WORD
Discrimination Bit 0
Discrimination Bit 1
Discrimination Bit 2
Discrimination Bit 3
Discrimination Bit 4
Discrimination Bit 5
Discrimination Bit 6
Discrimination Bit 7
Discrimination Bit 8
Discrimination Bit 9
Discrimination Bit 10
Discrimination Bit 11
Not Used
Not Used
Not Used
Not Used
CONFIG
(Configuration Word)
3.7.1
Bit Name
OSC0
OSC1
OSC2
OSC3
VLOWS
BRS
MTX4
TXEN
S3SET
XSER
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
OSCILLATOR TUNING BITS
(OSC0 AND OSC3)
These bits are used to tune the frequency of the
HCS201 internal clock oscillator to within ±10% of its
nominal value over temperature and voltage.
3.7.2
LOW VOLTAGE TRIP POINT
SELECT (VLOWS)
The low voltage trip point select bit (VLOWS) and the S3
setting bit (S3SET) are used to determine when to send
the VLOW signal to the receiver.
TABLE 3-4:
TRIP POINT SELECT
VLOWS
S3SET*
Trip Point
0
0
1
1
0
1
0
1
4.4
4.4
9
6.75
* See also Section 3.7.6
DS41098C-page 7
HCS201
3.7.3
BAUD RATE SELECT BITS (BRS)
BRS selects the speed of transmission and the code
word blanking. Table 3-5 shows how the bit is used to
select the different baud rates and Section 5.5 provides
detailed explanation in code word blanking.
TABLE 3-5:
BAUDRATE SELECT
0
Basic Pulse
Element
400 µs
Code Words
Transmitted
All
1
200 µs
1 out of 2
BRS
3.7.4
MINIMUM FOUR TRANSMISSIONS
(MTX4)
If this bit is cleared, only one code is completed if the
HCS201 is activated. If this bit is set, at least four complete code words are transmitted, even if code word
blanking is enabled.
3.7.5
TRANSMIT PULSE ENABLE (TXEN)
If this bit is cleared, no transmission pulse is transmitted before a transmission. If the bit is set, a START
pulse (1 TE long) is transmitted after button de-bouncing, before the preamble of the first code word.
3.7.6
S3 SETTING (S3SET)
This bit determines the value of S3 in the function code
during a transmission and the high trip point selected
by VLOWS in section 3.6.2. If this bit is cleared, S3 mirrors S2 during a transmission. If the S3SET bit is set,
S3 in the function code (Button Status) is always set,
independent of the value of S2.
3.7.7
EXTENDED SERIAL NUMBER
(XSER)
If this bit is set, a long 32-bit Serial Number is transmitted. If this bit is cleared, a standard 28-bit Serial Number
is transmitted followed by 4 bits of the function code
(Button Status).
DS41098C-page 8
 2001 Microchip Technology Inc.
HCS201
4.0
TRANSMITTED WORD
4.2
4.1
Code Word Format
The HCS201 transmits a 66-bit code word when a
button is pressed. The 66-bit word is constructed from
a Fixed Code portion and an Encrypted Code portion
(Figure 4-2).
The HCS201 code word is made up of several parts
(Figure 4-1). Each code word contains a 50% duty
cycle preamble, a header, 32 bits of encrypted data and
34 bits of fixed data followed by a guard period before
another code word can begin. Refer to Table 8-4 for
code word timing.
Code Word Organization
The 32 bits of Encrypted Data are generated from 4
button bits, 12 discrimination bits and the 16-bit sync
value. The encrypted portion alone provides up to four
billion changing code combinations.
The 34 bits of Fixed Code Data are made up of 2 status bits, 4 button bits and the 28-bit serial number. The
fixed and encrypted sections combined increase the
number of code combinations to 7.38 x 1019.
FIGURE 4-1:
CODE WORD FORMAT
TE TE TE
LOGIC ‘0’
LOGIC ‘1’
Bit
Period
50% Duty Cycle
Preamble
TP
FIGURE 4-2:
Header
TH
Encrypted Portion
of Transmission
THOP
VLOW
(1 bit)
MSb
Button
Status
S2 S1 S0 S3
Serial Number
(28 bits)
32 bits of Encrypted Portion
Button
Status
S2 S1 S0 S3
DISC
(12 bits)
Sync Counter
(16 bits)
66 Data bits
Transmitted
LSb first.
1
MSb
Guard
Time
TG
CODE WORD ORGANIZATION
34 bits of Fixed Portion
1
Fixed Portion of
Transmission
TFIX
VLOW
(1 bit)
Button
Status
1 1 1 1
Serial Number
(28 bits)
LSb
SEED
(32 bits)
LSb
SEED replaces Encrypted Portion when all button inputs are activated at the same time.
 2001 Microchip Technology Inc.
DS41098C-page 9
HCS201
4.3
Synchronous Transmission Mode
Synchronous Transmission mode can be used to clock
the code word out using an external clock.
To enter Synchronous Transmission mode, the Programming mode start-up sequence must be executed
as shown in Figure 4-3. If either S1 or S0 is set on the
falling edge of S2 (or S3), the device enters Synchronous Transmission mode. In this mode, it functions as
a normal transmitter, with the exception that the timing
of the PWM data string is controlled externally and 16
extra bits are transmitted at the end with the code word.
FIGURE 4-3:
The button code will be the S0, S1 value at the falling
edge of S2 or S3. The timing of the PWM data string is
controlled by supplying a clock on S2 or S3 and should
not exceed 20 kHz. The code word is the same as in
PWM mode with 16 reserved bits at the end of the
word. The reserved bits can be ignored. When in Synchronous Transmission mode S2 or S3 should not be
toggled until all internal processing has been completed as shown in Figure 4-4.
SYNCHRONOUS TRANSMISSION MODE (TXEN=0)
TPS TPH1 TPH2
t = 50ms
Preamble
Header
Data
PWM
S2
S[1:0]
FIGURE 4-4:
“01,10,11”
CODE WORD ORGANIZATION (SYNCHRONOUS TRANSMISSION MODE)
Fixed Portion
Reserved
(16 bits)
MSb
DS41098C-page 10
Padding
(2 bits)
Button
Status
S2 S1 S0 S3
Encrypted Portion
Serial Number
(28 bits)
Button
Status
S2 S1 S0 S3
DISC
(12 bits)
Sync Counter
(16 bits)
82 Data bits
Transmitted
LSb first.
LSb
 2001 Microchip Technology Inc.
HCS201
5.0
SPECIAL FEATURES
5.1
Code Word Completion
TABLE 5-1:
The code word completion feature ensures that entire
code words are transmitted, even if the button is
released before the code word is complete. If the button is held down beyond the time for one code word,
multiple code words will result. If another button is activated during a transmission, the active transmission
will be aborted and a new transmission will begin using
the new button information.
5.2
5.3
Auto-Shutoff
The auto-shutoff function automatically stops the device
from transmitting if a button inadvertently gets pressed
for a long period of time. This will prevent the device from
draining the battery if a button gets pressed while the
transmitter is in a pocket or purse. Time-out period is TTO.
5.4
Seed Transmission
In order to increase the level of security in a system, it
is possible for the receiver to implement what is known
as a secure learn function. This can be done by utilizing
the seed value stored in EEPROM, transmitted only
when all three button inputs are pressed at the same
time (Table 5-1). Instead of the normal key generation
inputs being used to create the crypt key, this seed
value is used.
FIGURE 5-1:
Function
S2
S1
S0
0
0
0
0
1
0
0
1
2
0
1
0
-
-
-
-
5
1
0
1
6
1
1
0
7
1
1
1
Standby
Hopping Code
Seed Code
VLOW: Voltage LOW Indicator
The VLOW bit is transmitted with every transmission
(Figure 8-4) and will be transmitted as a one if the
operating voltage has dropped below the low voltage trip
point. The trip point is selectable based on the battery
voltage being used. See Section 3.7.2 for a description
of how the low voltage select option is set. This VLOW
signal is transmitted so the receiver can give an audible
signal to the user that the transmitter battery is low.
PIN ACTIVATION TABLE
5.5
Blank Alternate Code Word
Federal Communications Commission (FCC) part 15
rules specify the limits on worst case average fundamental power and harmonics that can be transmitted in
a 100 ms window. For FCC approval purposes, it may
therefore be advantageous to minimize the transmission duty cycle. This can be achieved by minimizing the
duty cycle of the individual bits as well as by blanking
out consecutive code words. Blank Alternate Code
Word (BACW) may be used to reduce the average
power of a transmission by transmitting only every second code word (Figure 5-1). This is a selectable feature
that is determined in conjunction with the baud rate
selection bit BSL0.
Enabling the BACW option may likewise allow the user
to transmit a higher amplitude transmission as the time
averaged power is reduced. BACW effectively halves
the RF on time for a given transmission so the RF output power could theoretically be doubled while maintaining the same time averaged output power.
BLANK ALTERNATE CODE WORD (BACW)
Amplitude
BRS = 0
BRS = 1
A
Code Word
Code Word
Code Word
Code Word
2A
Time
 2001 Microchip Technology Inc.
DS41098C-page 11
HCS201
5.6
FIGURE 5-2:
Step Up Regulator
The integrated Step Up regulator can be used to
ensure the power supply voltage to the encoder and
the RF circuit (VDD), is constant independent of what
the battery voltage is (VDDB). Input on VDD pin is compared to VSTEP, the internal reference voltage. If VDD
falls below this voltage the STEP output is pulsed at
fSTEP. This output can be connected to an external circuit as illustrated in Figure 5-2, to provide a step up
voltage on the device.
APPLICATION CIRCUIT
VDD
L
D
The Step Up regulator is inactive when the device is not
transmitting.
S0
VDD
S1
STEP
S2
DATA
VDDB
R
Q
C
Tx out
VSS
2.0-6.0V
Note:
FIGURE 5-3:
Vdd(V)
Three button remote control with Step up regulator
Power to the Step up regulator is taken
from the VDDB pin. While VDD is limited to
a 3.5V minimum, VDDB minimum can be as
low as 2.0V for the Step Up circuit to start
operating.
External components sample values:
R = 5.1 KΩ
L = 390 uH
C = 1.0 uF
D = ZHCS400CT (40V 0.4A Zetex)
Q = 2N3904
TYPICAL LOADING CURVES (FIGURE 5-2 CIRCUIT)
8
7
6
5
4
3
2
1
0
Vddb=2V
Vddb=2.5V
Vddb=3V
Vddb=3.5V
0
5
10
15
20
Load(mA)
Note:
These are typical values not tested in production.
TABLE 5-2:
Symbol
STEP UP CIRCUIT CHARACTERISTICS
Parameters
Min.
Typ.
Max.
Units
fSTEP
Output frequency
125
200
250
kHz
VSTEP
Reference voltage
5.5
6.5
7.5
V
Note:
These parameters are characterized but not tested.
DS41098C-page 12
Conditions
VDDB = 3V
 2001 Microchip Technology Inc.
HCS201
PROGRAMMING THE HCS201
Twc. After every 16-bit word is written to the HCS201,
the HCS201 will signal that the write is complete by
sending out a train of ACK pulses, TACKH high, TACKL
low (if the oscillator was perfectly tuned) on DATA.
These will continue until S2 is dropped. The first pulse’s
width should NOT be used for calibration. At the end of
the programming cycle, the device can be verified
(Figure 6-2) by reading back the EEPROM. Reading is
done by clocking the S2 line and reading the data bits
on DATA. For security reasons, it is not possible to execute a verify function without first programming the
EEPROM. A Verify operation can only be done
once, immediately following the Program cycle.
When using the HCS201 in a system, the user will have
to program some parameters into the device including
the serial number and the secret key before it can be
used. The programming cycle allows the user to input
all 192 bits in a serial data stream, which are then
stored internally in EEPROM. Programming will be
initiated by forcing the DATA line high, after the S2 line
has been held high for the appropriate length of time
line (Table 6-1 and Figure 6-1). After the Program
mode is entered, a delay must be provided to the
device for the automatic bulk write cycle to complete.
This will write all locations in the EEPROM to an all
zeros pattern. The device can then be programmed by
clocking in 16 bits at a time, using S2 as the clock line
and DATA as the data in line. After each 16-bit word is
loaded, a programming delay is required for the internal
program cycle to complete. This delay can take up to
To ensure that the device does not accidentally enter Programming mode, DATA
should never be pulled high by the circuit
connected to it. Special care should be
taken when driving PNP RF transistors.
PROGRAMMING WAVEFORMS
Initiate Data
Polling Here
TCLKH
H
O
LD
TPBW
TCLKL
TDS
TP
Enter Program
Mode
DATA
(Data)
Bit 0
Bit 1
TWC
TDH
TCLKL
Bit 2
TA
TPS TPH1
C
KL
S2
(Clock)
Bit 3
Bit 14
TPH2
Ack
Ack
Bit 15
C
KH
FIGURE 6-1:
Note:
TA
6.0
Ack
Calibration Pulses
Write Cycle
Complete Here
Bit 16
Bit 17
Data for Word 1
Repeat for each word (12 times)
Note 1: S0 and S1 button inputs to be held to ground during the entire programming sequence.
FIGURE 6-2:
VERIFY WAVEFORMS
End of Programming Cycle
Beginning of Verify Cycle
Data from Word 0
DATA
(Data)
Bit190 Bit191
Ack
TWC
Bit 0
Bit 1 Bit 2
Bit 3
Bit 14
Bit 15
Bit 16 Bit 17
Bit190 Bit191
TDV
S2
(Clock)
Note: If a Verify operation is to be done, then it must immediately follow the Program cycle.
 2001 Microchip Technology Inc.
DS41098C-page 13
HCS201
TABLE 6-1:
PROGRAMMING/VERIFY TIMING REQUIREMENTS
VDD = 5.0V ± 10%, 25° C ± 5 °C
Parameter
Program mode setup time
Hold time 1
Hold time 2
Bulk Write time
Program delay time
Program cycle time
Clock low time
Clock high time
Data setup time
Data hold time
Data out valid time
Hold time
Acknowledge low time
Acknowledge high time
DS41098C-page 14
Symbol
Min.
Max.
Units
TPS
TPH1
TPH2
TPBW
TPROG
TWC
TCLKL
TCLKH
TDS
TDH
TDV
TPHOLD
TACKL
TACKH
2
4.0
50
4.0
4.0
50
50
50
0
18
—
100
800
800
5.0
—
—
—
—
—
—
—
—
—
30
—
—
—
ms
ms
µs
ms
ms
ms
µs
µs
µs
µs
µs
µs
µs
µs
 2001 Microchip Technology Inc.
HCS201
7.0
INTEGRATING THE HCS201
INTO A SYSTEM
Use of the HCS201 in a system requires a compatible
decoder. This decoder is typically a microcontroller with
compatible firmware. Microchip will provide (via a
license agreement) firmware routines that accept
transmissions from the HCS201 and decrypt the
hopping code portion of the data stream. These
routines provide system designers the means to
develop their own decoding system.
7.1
Learning a Transmitter to a
Receiver
A transmitter must first be ’learned’ by a decoder before
its use is allowed in the system. Several learning strategies are possible, Figure 7-1 details a typical learn
sequence. Core to each, the decoder must minimally
store each learned transmitter’s serial number and current synchronization counter value in EEPROM. Additionally, the decoder typically stores each transmitter’s
unique crypt key. The maximum number of learned
transmitters will therefore be relative to the available
EEPROM.
A transmitter’s serial number is transmitted in the clear
but the synchronization counter only exists in the code
word’s encrypted portion. The decoder obtains the
counter value by decrypting using the same key used
to encrypt the information. The KEELOQ algorithm is a
symmetrical block cipher so the encryption and decryption keys are identical and referred to generally as the
crypt key. The encoder receives its crypt key during
manufacturing. The decoder is programmed with the
ability to generate a crypt key as well as all but one
required input to the key generation routine; typically
the transmitter’s serial number.
Figure 7-1 summarizes a typical learn sequence. The
decoder receives and authenticates a first transmission; first button press. Authentication involves generating the appropriate crypt key, decrypting, validating
the correct key usage via the discrimination bits and
buffering the counter value. A second transmission is
received and authenticated. A final check verifies the
counter values were sequential; consecutive button
presses. If the learn sequence is successfully complete, the decoder stores the learned transmitter’s
serial number, current synchronization counter value
and appropriate crypt key. From now on the crypt key
will be retrieved from EEPROM during normal operation instead of recalculating it for each transmission
received.
FIGURE 7-1:
TYPICAL LEARN
SEQUENCE
Enter Learn
Mode
Wait for Reception
of a Valid Code
Generate Key
from Serial Number
Use Generated Key
to Decrypt
Compare Discrimination
Value with Fixed Value
Equal
?
No
Yes
Wait for Reception
of Second Valid Code
Use Generated Key
to Decrypt
Compare Discrimination
Value with Fixed Value
Equal
?
No
Yes
Counters
Sequential
?
Yes
No
Learn successful Store:
Learn
Unsuccessful
Serial number
Encryption key
Synchronization counter
Exit
Certain learning strategies have been patented and
care must be taken not to infringe.
 2001 Microchip Technology Inc.
DS41098C-page 15
HCS201
7.2
Decoder Operation
7.3
Figure 7-2 summarizes normal decoder operation. The
decoder waits until a transmission is received. The
received serial number is compared to the EEPROM
table of learned transmitters to first determine if this
transmitter’s use is allowed in the system. If from a
learned transmitter, the transmission is decrypted
using the stored crypt key and authenticated via the
discrimination bits for appropriate crypt key usage. If
the decryption was valid the synchronization value is
evaluated.
FIGURE 7-2:
TYPICAL DECODER
OPERATION
Start
No
Transmission
Received
?
Yes
No
Is
Decryption
Valid
?
Yes
No
Is
Counter
Within 16
?
No
No
Is
Counter
Within 32K
?
Yes
Save Counter
in Temp Location
DS41098C-page 16
Yes
The KEELOQ technology patent scope includes a
sophisticated synchronization technique that does not
require the calculation and storage of future codes. The
technique securely blocks invalid transmissions while
providing transparent resynchronization to transmitters
inadvertently activated away from the receiver.
Figure 7-3 shows a 3-partition, rotating synchronization
window. The size of each window is optional but the
technique is fundamental. Each time a transmission is
authenticated, the intended function is executed and
the transmission’s synchronization counter value is
stored in EEPROM. From the currently stored counter
value there is an initial "Single Operation" forward window of 16 codes. If the difference between a received
synchronization counter and the last stored counter is
within 16, the intended function will be executed on the
single button press and the new synchronization
counter will be stored. Storing the new synchronization
counter value effectively rotates the entire synchronization window.
A "Double Operation" (resynchronization) window further exists from the Single Operation window up to 32K
codes forward of the currently stored counter value. It
is referred to as "Double Operation" because a transmission with synchronization counter value in this window will require an additional, sequential counter
transmission prior to executing the intended function.
Upon receiving the sequential transmission the
decoder executes the intended function and stores the
synchronization counter value. This resynchronization
occurs transparently to the user as it is human nature
to press the button a second time if the first was unsuccessful.
Does
Serial Number
Match
?
Yes
Decrypt Transmission
No
Synchronization with Decoder
(Evaluating the Counter)
Execute
Command
and
Update
Counter
The third window is a "Blocked Window" ranging from
the double operation window to the currently stored
synchronization counter value. Any transmission with
synchronization counter value within this window will
be ignored. This window excludes previously used,
perhaps code-grabbed transmissions from accessing
the system.
Note:
The synchronization method described in
this section is only a typical implementation
and because it is usually implemented in
firmware, it can be altered to fit the needs
of a particular system.
 2001 Microchip Technology Inc.
HCS201
FIGURE 7-3:
SYNCHRONIZATION WINDOW
Entire Window
rotates to eliminate
use of previously
used codes
Blocked
Window
(32K Codes)
Stored
Synchronization
Counter Value
Double Operation
(resynchronization)
Window
(32K Codes)
 2001 Microchip Technology Inc.
Single Operation
Window
(16 Codes)
DS41098C-page 17
HCS201
8.0
ELECTRICAL CHARACTERISTICS
TABLE 8-1:
ABSOLUTE MAXIMUM RATINGS
Symbol
Item
Rating
Units
VDD
Supply voltage
-0.3 to 13.5
V
VIN
Input voltage
-0.3 to VDD + 0.3
V
VOUT
Output voltage
-0.3 to VDD + 0.3
V
IOUT
Max output current
50
mA
TSTG
Storage temperature
-55 to +125
C (Note 1)
TLSOL
Lead soldering temp
300
C (Note 1)
Note 1: Stresses above those listed under “ABSOLUTE MAXIMUM RATINGS” may cause permanent damage to
the device.
TABLE 8-2:
DC CHARACTERISTICS
Commercial (C): Tamb = 0°C to +70°C
Industrial
(I): Tamb = -40°C to +85°C
3.5V < VDD < 5.0V
5.0V < VDD < 13.0V
Parameter
Sym.
Min.
Typ.1
Max.
Min.
Typ.1
Max.
Unit
Operating
Current (avg)2
ICC
—
0.2
0.5
—
—
1.5
—
2
mA
mA
Standby
Current
ICCS
—
0.1
1.0
—
0.1
1.0
µA
Auto-shutoff
Current3,4
ICCS
—
40
75
—
160
300
µA
High Level
Input Voltage
VIH
0.55VDD
—
VDD+0.3
2.75
—
VDD+0.3
V
Low level
Input Voltage
VIL
-0.3
—
0.15VDD
-0.3
—
0.75
V
High level
Output
Voltage
VOH
0.6VDD
—
—
—
3.3
—
—
V
V
IOH = -1.0 mA VDD = 3.5V
IOH = -2.0 mA VDD = 12V
Low Level
Output
Voltage
VOL
—
—
0.08VDD
—
—
—
0.4
V
V
IOL = 1.0 mA VDD = 5V
IOL = 2.0 mA VDD = 12V
Pull-down
Resistance;
S0-S2
RSO-2
40
60
80
40
60
80
kΩ
VDD = 4.0V
Pull-down
Resistance;
DATA
RDATA
80
120
160
80
120
160
kΩ
VDD = 4.0V
Conditions
Note 1: Typical values are at 25°C.
2: No load.
3: Auto-shutoff current specification does not include the current through the input pull-down resistors.
4: These values are characterized but not tested.
DS41098C-page 18
 2001 Microchip Technology Inc.
HCS201
FIGURE 8-1:
POWER-UP AND TRANSMIT TIMING
Button Press
Detect
Multiple Code Word Transmission
TBP
TTD
TDB
DATA
Output
Code
Word
1
TS
Code
Word
2
Code
Word
3
Code
Word
4
Code
Word
n
TTO
Button
Input
Sn
POWER-UP AND TRANSMIT TIMING(2)
TABLE 8-3:
Standard Operating Conditions (unless otherwise specified):
Commercial(C): Tamb = 0°C to +70°C
Industrial(I): Tamb = -40°C to +85°C
Symbol
TBP
Parameter
Min.
Time to second button press
10 + Code
Word
12
6
Typ.
Max.
Unit
Conditions
26 + Code
Word
26
20
ms
(Note 1)
Transmit delay from button detect
ms
TTD
TDB
Debounce Delay
ms
TTO
Auto-shutoff time-out period
27
s
Ts
START Pulse Delay
4.5
ms
Note 1: TBP is the time in which a second button can be pressed without completion of the first code word
(the intention was to press the combination of buttons).
2: Typical values - not tested in production.
FIGURE 8-2:
CODE WORD FORMAT
TE TE TE
LOGIC ‘0’
LOGIC ‘1’
Bit Period
TBP
50% Duty Cycle
Preamble
TP
 2001 Microchip Technology Inc.
Header
TH
Encrypted Portion
of Transmission
THOP
Fixed Portion of
Transmission
TFIX
Guard
Time
TG
DS41098C-page 19
HCS201
FIGURE 8-3:
CODE WORD FORMAT: PREAMBLE/HEADER PORTION
P1
P12
Bit 0 Bit 1
23 TE 50% Duty Cycle Preamble
FIGURE 8-4:
10 TE Header
CODE WORD FORMAT: DATA PORTION (XSER=0)
Serial Number
MSB LSB
LSB
Bit 0 Bit 1
Header
Data Bits
MSB
S0
S1
S2
VLOW RPT
Guard
Time
Fixed Portion
CODE WORD TRANSMISSION TIMING REQUIREMENTS
VDD = +3.5 to 6.0V
Commercial (C): Tamb = 0°C to +70°C
Industrial
(I): Tamb = -40°C to +85°C
Symbol
S3
Status
Bit 30 Bit 31 Bit 32 Bit 33 Bit 58 Bit 59 Bit 60 Bit 61 Bit 62 Bit 63 Bit 64 Bit 65
Encrypted Portion
TABLE 8-4:
Button Code
Characteristic
Code Words Transmitted
All
1 out of 2
Number
of TE
Min.
Typ.
Max.
Min.
Typ.
Max.
Units
TE
Basic pulse element
1
360
400
440
180
200
220
µs
TBP
PWM bit pulse width
3
1.08
1.2
1.32
0.54
0.6
0.66
ms
TP
Preamble duration
23
8.64
9.2
10.56
4.32
4.6
5.28
ms
TH
Header duration
10
3.6
4.0
4.4
1.8
2.0
2.2
ms
THOP
Hopping code duration
96
34.56
38.4
42.24
17.28
19.2
21.12
ms
TFIX
Fixed code duration
102
36.72
40.8
44.88
18.36
20.4
22.44
ms
TG
Guard Time
39
14.04
15.6
17.16
7.02
7.8
8.58
ms

Total Transmit Time
271
97.56
108.4
119.24
48.78
54.2
59.62
ms

PWM data rate

925
833
757
1851
1667
1515
bps
Note 1: The timing parameters are not tested but derived from the oscillator clock.
DS41098C-page 20
 2001 Microchip Technology Inc.
HCS201
9.0
PACKAGING INFORMATION
9.1
Package Marking Information
8-Lead PDIP (300 mil)
Example
XXXXXXXX
XXXXXNNN
YYWW
HCS201
XXXXXNNN
0025
8-Lead SOIC (150 mil)
XXXXXXX
XXXYYWW
NNN
Legend: XX...X
YY
WW
NNN
Note:
*
Example
HCS201
XXX0025
NNN
Customer specific information*
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line thus limiting the number of available characters
for customer specific information.
Standard OTP marking consists of Microchip part number, year code, week code, facility code, mask
rev#, and assembly code. For OTP marking beyond this, certain price adders apply. Please check with
your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP price.
 2001 Microchip Technology Inc.
DS41098C-page 21
HCS201
9.2
Package Details
8-Lead Plastic Dual In-line (P) – 300 mil (PDIP)
E1
D
2
n
1
α
E
A2
A
L
c
A1
β
B1
p
eB
B
Units
Dimension Limits
n
p
Number of Pins
Pitch
Top to Seating Plane
Molded Package Thickness
Base to Seating Plane
Shoulder to Shoulder Width
Molded Package Width
Overall Length
Tip to Seating Plane
Lead Thickness
Upper Lead Width
Lower Lead Width
Overall Row Spacing
Mold Draft Angle Top
Mold Draft Angle Bottom
* Controlling Parameter
§ Significant Characteristic
A
A2
A1
E
E1
D
L
c
§
B1
B
eB
α
β
MIN
.140
.115
.015
.300
.240
.360
.125
.008
.045
.014
.310
5
5
INCHES*
NOM
MAX
8
.100
.155
.130
.170
.145
.313
.250
.373
.130
.012
.058
.018
.370
10
10
.325
.260
.385
.135
.015
.070
.022
.430
15
15
MILLIMETERS
NOM
8
2.54
3.56
3.94
2.92
3.30
0.38
7.62
7.94
6.10
6.35
9.14
9.46
3.18
3.30
0.20
0.29
1.14
1.46
0.36
0.46
7.87
9.40
5
10
5
10
MIN
MAX
4.32
3.68
8.26
6.60
9.78
3.43
0.38
1.78
0.56
10.92
15
15
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-001
Drawing No. C04-018
DS41098C-page 22
 2001 Microchip Technology Inc.
HCS201
8-Lead Plastic Small Outline (SN) – Narrow, 150 mil (SOIC)
E
E1
p
D
2
B
n
1
α
h
45°
c
A2
A
φ
β
L
Units
Dimension Limits
n
p
Number of Pins
Pitch
Overall Height
Molded Package Thickness
Standoff §
Overall Width
Molded Package Width
Overall Length
Chamfer Distance
Foot Length
Foot Angle
Lead Thickness
Lead Width
Mold Draft Angle Top
Mold Draft Angle Bottom
* Controlling Parameter
§ Significant Characteristic
A
A2
A1
E
E1
D
h
L
φ
c
B
α
β
MIN
.053
.052
.004
.228
.146
.189
.010
.019
0
.008
.013
0
0
A1
INCHES*
NOM
8
.050
.061
.056
.007
.237
.154
.193
.015
.025
4
.009
.017
12
12
MAX
.069
.061
.010
.244
.157
.197
.020
.030
8
.010
.020
15
15
MILLIMETERS
NOM
8
1.27
1.35
1.55
1.32
1.42
0.10
0.18
5.79
6.02
3.71
3.91
4.80
4.90
0.25
0.38
0.48
0.62
0
4
0.20
0.23
0.33
0.42
0
12
0
12
MIN
MAX
1.75
1.55
0.25
6.20
3.99
5.00
0.51
0.76
8
0.25
0.51
15
15
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed
.010” (0.254mm) per side.
JEDEC Equivalent: MS-012
Drawing No. C04-057
 2001 Microchip Technology Inc.
DS41098C-page 23
HCS201
ON-LINE SUPPORT
Microchip provides on-line support on the Microchip
World Wide Web (WWW) site.
The web site is used by Microchip as a means to make
files and information easily available to customers. To
view the site, the user must have access to the Internet
and a web browser, such as Netscape or Microsoft
Explorer. Files are also available for FTP download
from our FTP site.
Connecting to the Microchip Internet Web
Site
Systems Information and Upgrade Hot
Line
The Systems Information and Upgrade Line provides
system users a listing of the latest versions of all of
Microchip's development systems software products.
Plus, this line provides information on how customers
can receive any currently available upgrade kits.The
Hot Line Numbers are:
1-800-755-2345 for U.S. and most of Canada, and
1-480-792-7302 for the rest of the world.
The Microchip web site is available by using your
favorite Internet browser to attach to:
www.microchip.com
The file transfer site is available by using an FTP service to connect to:
ftp://ftp.microchip.com
The web site and file transfer site provide a variety of
services. Users may download files for the latest
Development Tools, Data Sheets, Application Notes,
User’s Guides, Articles and Sample Programs. A variety of Microchip specific business information is also
available, including listings of Microchip sales offices,
distributors and factory representatives. Other data
available for consideration is:
• Latest Microchip Press Releases
• Technical Support Section with Frequently Asked
Questions
• Design Tips
• Device Errata
• Job Postings
• Microchip Consultant Program Member Listing
• Links to other useful web sites related to
Microchip Products
• Conferences for products, Development Systems,
technical information and more
• Listing of seminars and events
DS41098C-page 24
 2001 Microchip Technology Inc.
HCS201
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation
can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-7578.
Please list the following information, and use this outline to provide us with your comments about this Data Sheet.
To:
Technical Publications Manager
RE:
Reader Response
Total Pages Sent
From: Name
Company
Address
City / State / ZIP / Country
Telephone: (_______) _________ - _________
FAX: (______) _________ - _________
Application (optional):
Would you like a reply?
Device: HCS201
Y
N
Literature Number: DS41098C
Questions:
1. What are the best features of this document?
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this data sheet easy to follow? If not, why?
4. What additions to the data sheet do you think would enhance the structure and subject?
5. What deletions from the data sheet could be made without affecting the overall usefulness?
6. Is there any incorrect or misleading information (what and where)?
7. How would you improve this document?
8. How would you improve our software, systems, and silicon products?
 2001 Microchip Technology Inc.
DS41098C-page 25
HCS201
NOTES:
DS41098C-page 26
 2001 Microchip Technology Inc.
Microchip’s Secure Data Products are covered by some or all of the following patents:
Code hopping encoder patents issued in Europe, U.S.A., and R.S.A. — U.S.A.: 5,517,187; Europe: 0459781; R.S.A.: ZA93/4726
Secure learning patents issued in the U.S.A. and R.S.A. — U.S.A.: 5,686,904; R.S.A.: 95/5429
Information contained in this publication regarding device
applications and the like is intended through suggestion only
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
No representation or warranty is given and no liability is
assumed by Microchip Technology Incorporated with respect
to the accuracy or use of such information, or infringement of
patents or other intellectual property rights arising from such
use or otherwise. Use of Microchip’s products as critical components in life support systems is not authorized except with
express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property
rights.
Trademarks
The Microchip name and logo, the Microchip logo, FilterLab,
KEELOQ, MPLAB, PIC, PICmicro, PICMASTER, PICSTART,
PRO MATE, SEEVAL and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A. and other countries.
dsPIC, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB,
In-Circuit Serial Programming, ICSP, ICEPIC, microID,
microPort, Migratable Memory, MPASM, MPLIB, MPLINK,
MPSIM, MXDEV, PICC, PICDEM, PICDEM.net, rfPIC, Select
Mode and Total Endurance are trademarks of Microchip
Technology Incorporated in the U.S.A.
Serialized Quick Turn Programming (SQTP) is a service mark
of Microchip Technology Incorporated in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2001, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
Microchip received QS-9000 quality system
certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999. The
Company’s quality system processes and
procedures are QS-9000 compliant for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping
devices, Serial EEPROMs and microperipheral
products. In addition, Microchip’s quality
system for the design and manufacture of
development systems is ISO 9001 certified.
 2001 Microchip Technology Inc.
DS41098C - page 27
WORLDWIDE SALES AND SERVICE
AMERICAS
ASIA/PACIFIC
Japan
Corporate Office
Australia
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200 Fax: 480-792-7277
Technical Support: 480-792-7627
Web Address: http://www.microchip.com
Microchip Technology Australia Pty Ltd
Suite 22, 41 Rawson Street
Epping 2121, NSW
Australia
Tel: 61-2-9868-6733 Fax: 61-2-9868-6755
Microchip Technology Japan K.K.
Benex S-1 6F
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa, 222-0033, Japan
Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Rocky Mountain
China - Beijing
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7966 Fax: 480-792-7456
Microchip Technology Consulting (Shanghai)
Co., Ltd., Beijing Liaison Office
Unit 915
Bei Hai Wan Tai Bldg.
No. 6 Chaoyangmen Beidajie
Beijing, 100027, No. China
Tel: 86-10-85282100 Fax: 86-10-85282104
Atlanta
500 Sugar Mill Road, Suite 200B
Atlanta, GA 30350
Tel: 770-640-0034 Fax: 770-640-0307
Boston
2 Lan Drive, Suite 120
Westford, MA 01886
Tel: 978-692-3848 Fax: 978-692-3821
Chicago
333 Pierce Road, Suite 180
Itasca, IL 60143
Tel: 630-285-0071 Fax: 630-285-0075
Dallas
4570 Westgrove Drive, Suite 160
Addison, TX 75001
Tel: 972-818-7423 Fax: 972-818-2924
Dayton
Two Prestige Place, Suite 130
Miamisburg, OH 45342
Tel: 937-291-1654 Fax: 937-291-9175
Detroit
Tri-Atria Office Building
32255 Northwestern Highway, Suite 190
Farmington Hills, MI 48334
Tel: 248-538-2250 Fax: 248-538-2260
Kokomo
2767 S. Albright Road
Kokomo, Indiana 46902
Tel: 765-864-8360 Fax: 765-864-8387
Los Angeles
18201 Von Karman, Suite 1090
Irvine, CA 92612
Tel: 949-263-1888 Fax: 949-263-1338
New York
150 Motor Parkway, Suite 202
Hauppauge, NY 11788
Tel: 631-273-5305 Fax: 631-273-5335
San Jose
Microchip Technology Inc.
2107 North First Street, Suite 590
San Jose, CA 95131
Tel: 408-436-7950 Fax: 408-436-7955
Toronto
6285 Northam Drive, Suite 108
Mississauga, Ontario L4V 1X5, Canada
Tel: 905-673-0699 Fax: 905-673-6509
China - Chengdu
Microchip Technology Consulting (Shanghai)
Co., Ltd., Chengdu Liaison Office
Rm. 2401, 24th Floor,
Ming Xing Financial Tower
No. 88 TIDU Street
Chengdu 610016, China
Tel: 86-28-6766200 Fax: 86-28-6766599
China - Fuzhou
Microchip Technology Consulting (Shanghai)
Co., Ltd., Fuzhou Liaison Office
Rm. 531, North Building
Fujian Foreign Trade Center Hotel
73 Wusi Road
Fuzhou 350001, China
Tel: 86-591-7557563 Fax: 86-591-7557572
China - Shanghai
Microchip Technology Consulting (Shanghai)
Co., Ltd.
Room 701, Bldg. B
Far East International Plaza
No. 317 Xian Xia Road
Shanghai, 200051
Tel: 86-21-6275-5700 Fax: 86-21-6275-5060
China - Shenzhen
Microchip Technology Consulting (Shanghai)
Co., Ltd., Shenzhen Liaison Office
Rm. 1315, 13/F, Shenzhen Kerry Centre,
Renminnan Lu
Shenzhen 518001, China
Tel: 86-755-2350361 Fax: 86-755-2366086
Hong Kong
Microchip Technology Hongkong Ltd.
Unit 901-6, Tower 2, Metroplaza
223 Hing Fong Road
Kwai Fong, N.T., Hong Kong
Tel: 852-2401-1200 Fax: 852-2401-3431
India
Microchip Technology Inc.
India Liaison Office
Divyasree Chambers
1 Floor, Wing A (A3/A4)
No. 11, O’Shaugnessey Road
Bangalore, 560 025, India
Tel: 91-80-2290061 Fax: 91-80-2290062
Korea
Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea 135-882
Tel: 82-2-554-7200 Fax: 82-2-558-5934
Singapore
Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Singapore, 188980
Tel: 65-334-8870 Fax: 65-334-8850
Taiwan
Microchip Technology Taiwan
11F-3, No. 207
Tung Hua North Road
Taipei, 105, Taiwan
Tel: 886-2-2717-7175 Fax: 886-2-2545-0139
EUROPE
Denmark
Microchip Technology Nordic ApS
Regus Business Centre
Lautrup hoj 1-3
Ballerup DK-2750 Denmark
Tel: 45 4420 9895 Fax: 45 4420 9910
France
Microchip Technology SARL
Parc d’Activite du Moulin de Massy
43 Rue du Saule Trapu
Batiment A - ler Etage
91300 Massy, France
Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Germany
Microchip Technology GmbH
Gustav-Heinemann Ring 125
D-81739 Munich, Germany
Tel: 49-89-627-144 0 Fax: 49-89-627-144-44
Italy
Microchip Technology SRL
Centro Direzionale Colleoni
Palazzo Taurus 1 V. Le Colleoni 1
20041 Agrate Brianza
Milan, Italy
Tel: 39-039-65791-1 Fax: 39-039-6899883
United Kingdom
Arizona Microchip Technology Ltd.
505 Eskdale Road
Winnersh Triangle
Wokingham
Berkshire, England RG41 5TU
Tel: 44 118 921 5869 Fax: 44-118 921-5820
10/01/01
DS41098C-page 28
 2001 Microchip Technology Inc.