hcs362 Microchip Technology Inc., hcs362 Datasheet - Page 13

• Manufacturer Part Number: hcs362
• Description: Keeloq Code Hopping Encoder
• Manufacturer: Microchip Technology Inc.

3.3
A seed transmission transmits a code word that con-
sists of 60 bits of fixed data that is stored in the
EEPROM. This can be used for secure learning of
encoders or whenever a fixed code transmission is
required. The seed code word further contains the
function code and the status information (V
and QUEUE) as configured for normal code hopping
code words. The seed code word format is shown in
Figure 3-9. The function code for seed code words is
always ‘
FIGURE 3-9:
3.3.1
The button combination (
Seed code word can be selected with the Seed and
SeedC (
options as shown in Table 3-1 and Table 3-2:
TABLE 3-1:
TABLE 3-2:
SEED
SEED
Note:
Note:
2002 Microchip Technology Inc.
With QUEN = 1
Q1 Q0 C1 C0
00
01
10
11
00
01
10
11
(2 bits)
QUE
1111b
Seed Code Word Data Format
SEED
(2 bits)
*Limited Seed
*Limited Seed
SEED OPTIONS
CRC
Fixed Portion
’.
[
(9 bits)
0..1
S[3210]
S[3210]
0101*
1001*
0101
0101
1001
1001
SEED CODE WORD FORMAT
SEED OPTIONS (SEEDC = 0)
Seed
SEED OPTIONS (SEEDC = 1)
Seed
(1-bit)
V
-
-
LOW
S2 S1 S0
] and
S[3210]
(4 bits)
BUT
SEEDC
1.6 s Delayed Seed
3.2 s Delayed Seed
S3
) for transmitting a
) configuration
S[3210]
S[3210]
0001*
0011*
0001
0011
-
-
-
-
LOW
, CRC
Preliminary
Seed code words can be configured as follows:
• Enabled permanently.
• Disabled permanently.
• Enabled until the synchronization counter is
• The time before the seed code word is transmitted
Example A): Selecting
makes SEED transmission available every time the
combination of buttons S3 and S0 is pressed simulta-
neously, but Delayed Seed mode is not available.
Example B): Selecting
makes SEED transmission available only for a limited
time (only up to 128 times). The combination of buttons
S2 and S0 produces an immediate transmission of the
SEED code. Pressing and holding for more than 1.6
seconds the S0 button alone, produces the SEED code
word transmission (Delayed Seed).
greater than 7Fh, this configuration is often
referred to as Limited Seed.
can be set to 1.6 s or 3.2 s, this configuration is
often referred to as Delayed Seed. When this
option is selected, the HCS362 will transmit a
code hopping code word for 1.6 s or 3.2 s, before
the seed code word is transmitted.
SEED Code
(60 bits)
SEED
Transmission Direction LSB First
SEEDC = 0
SEEDC = 1
HCS362
DS40189D-page 13
and
and
SEED = 11
SEED = 01
:
: