HCS360-IP Microchip Technology, HCS360-IP Datasheet - Page 13

• Manufacturer Part Number: HCS360-IP
• Description: KEELOQ CODE HOPPING ENCODER
• Manufacturer: Microchip Technology

6.0
When using the HCS360 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
192 bits in a serial data stream, which are then stored
internally in EEPROM. Programming will be initiated by
forcing the PWM line high, after the S3 line has been
held high for the appropriate length of time. S0 and S1
(Table 6-1 and Figure 6-1). The device can then be pro-
grammed by clocking in 16 bits at a time, followed by
the word’s complement using S3 or S2 as the clock line
and PWM as the data in line. After each 16-bit word is
FIGURE 6-1:
FIGURE 6-2:
TABLE 6-1
should be held low during the entire program cycle
V
25 C
Program mode setup time
Hold time 1
Program cycle time
Clock low time
Clock high time
Data setup time
Data hold time
Data out valid time
(Clock)
S2/S3
(Data)
1996 Microchip Technology Inc.
PWM
DD
Note 1: Unused button inputs to be held to ground during the entire programming sequence.
= 5.0V
Enter Program
Note: If a Verify operation is to be done, then it must immediately follow the Program cycle.
5 C
PROGRAMMING THE HCS360
Parameter
Mode
2: The V
Programming Cycle
(Clock)
S2/S3
(Data)
PWM
Bit190
10%
End of
Bit191
PROGRAMMING WAVEFORMS
VERIFY WAVEFORMS
PROGRAMMING/VERIFY TIMING REQUIREMENTS
T
DD
2
T
T
pin must be taken to ground after a program/verify cycle.
1
WC
allows the user to input all
Bit 0
T
CLKL
Begin Verify Cycle Here
Bit 1
T
Symbol
Bit 2
DS
T
T
Bit 0
T
T
T
T
CLKH
CLKL
T
T
WC
DH
DS
DV
Repeat 12 times for each word
2
1
T
Bit 3
DH
Data for Word 0 (KEY_0)
Bit 1 Bit 2
Bit 14 Bit 15
T
Preliminary
DV
T
CLKH
Bit 3
Data in Word 0
Bit 0
Min.
9.0
25
25
18
—
—
0
0
loaded, a programming delay is required for the internal
program cycle to complete. The acknowledge can read
back after the programming delay (T
word and its complement have been downloaded, an
automatic bulk write is performed. This delay can take
up to Twc. 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 S3 line and
reading the data bits on PWM. 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 pro-
gram cycle.
Bit 1 Bit 2
Bit 14
Bit 3
Bit 15
Bit 14 Bit 15
Max.
4.0
—
30
—
—
—
—
24
Bit 16 Bit 17
T
WC
HCS360
WC
DS40152C-page 13
Bit 16 Bit 17
Data for Word 1
Acknowledge
Bit190 Bit191
). After the first
Units
ms
ms
ms
s
s
s
s
s