HCS201T/SN Microchip Technology, HCS201T/SN Datasheet - Page 7
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HCS201T/SN
Manufacturer Part Number
HCS201T/SN
Description
IC CODE HOPP ENCODER 7FUNC 8SOIC
Manufacturer
Microchip Technology
Type
Code Hopping Encoderr
Specifications of HCS201T/SN
Applications
Remote Secure Access, Keyless Entry
Mounting Type
Surface Mount
Package / Case
8-SOIC (3.9mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
HCS201T/SN
Manufacturer:
MICROCHIP
Quantity:
12 000
Part Number:
HCS201T/SN
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
Company:
Part Number:
HCS201T/SN028
Manufacturer:
PANASONIC
Quantity:
4 623
3.3
Must be initialized to 0000H.
3.4
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
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 imple-
ment the secure learn feature or use this fixed code
word as part of a different key generation/tracking pro-
cess.
TABLE 3-2:
3.6
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 discrimi-
nation value was programmed as the 12 LSb’s of the
Bit Number
2001 Microchip Technology Inc.
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
SER_0, SER_1
(Encoder Serial Number)
SEED_0, SEED_1 (Seed Word)
DISC
(Discrimination Word)
Reserved
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
DISCRIMINATION WORD
Bit Description
serial number then it may merely be compared to the
respective bits of the received serial number; saving
EEPROM space.
3.7
The Configuration Word is a 16-bit word stored in
EEPROM array that is used by the device to store infor-
mation used during the encryption process, as well as
the status of option configurations. Further explana-
tions of each of the bits are described in the following
sections.
TABLE 3-3:
3.7.1
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
The low voltage trip point select bit (V
setting bit (S3SET) are used to determine when to send
the V
TABLE 3-4:
* See also Section 3.7.6
Bit Number
LOW
V
10
12
13
14
15
11
0
1
2
3
4
5
6
7
8
9
LOWS
0
0
1
1
CONFIG
(Configuration Word)
signal to the receiver.
OSCILLATOR TUNING BITS
(OSC0 AND OSC3)
LOW VOLTAGE TRIP POINT
SELECT (V
OSC0
OSC1
OSC2
OSC3
V
BRS
MTX4
TXEN
S3SET
XSER
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
LOWS
TRIP POINT SELECT
CONFIGURATION WORD
S3SET*
LOWS
0
1
0
1
Bit Name
)
HCS201
LOWS
DS41098C-page 7
Trip Point
) and the S3
6.75
4.4
4.4
9