hcs515 Microchip Technology Inc., hcs515 Datasheet - Page 16

• Manufacturer Part Number: hcs515
• Description: Keeloq Code Hopping Decoder Keeloq Code Hopping Decoder
• Manufacturer: Microchip Technology Inc.

HCS515
5.2
The programming command consists of the following:
• Command Request Sequence (A to B)
• Command Byte (B to C)
• Configuration Byte (C to D)
• Manufacturer’s Code Eight Data Bytes (D to G)
• Activation and Acknowledge Sequence (G to H)
FIGURE 5-1:
TABLE 5-1:
DS40183D-page 16
T
T
T
T
T
T
T
T
T
T
Symbol
START
CLKH
CLKL
ACK
HCS515
REQ
RESP
WTH
WTL
DS
DATA
Note:
C
Data
Data
CLK
A
Programming Waveform
T
T
START Command
REQ
RESP
d.o.d. - depends on decoder status
These parameters are characterized but not tested
Command request time
Acknowledge time
Command request to first command bit
Clock high time
Clock low time
Data hold time
Command last bit to data first bit
Command acknowledge time
Acknowledge respond time
Clock low to next command
T
START
PROGRAMMING WAVEFORM
PROGRAMMING COMMAND
B
LSB
T
CLKL
Command Byte
Parameters
T
CLKH
MSB
T
DATA
T
DS
C
LSB
Configuration Byte
MSB
T
Sugg. Value
DATA
D
d.o.d.
d.o.d.
100
100
100
100
100
100
100
50
LSB
Least Significant Byte
5.3
A total of 80 bits are clocked into the decoder. The 8-bit
command byte is clocked in first, followed by the 8-bit
configuration byte and the 64-bit manufacturer’s code.
The data must be clocked in Least Significant bit (LSb)
first. The decoder will then encrypt the manufacturer’s
code using the decoder’s unique 64-bit EEPROM
encoder decryption key. After completion of the pro-
gramming EEPROM, the decoder will acknowledge by
taking the data line high (G to H). If the data line goes
high within 30 ms after the clock goes high, program-
ming also fails.
MSB
Programming Data String
T
DATA
0.005
Min.
10
20
20
20
14
10
30
20
10
E
F
LSB
Most Significant Byte
2002 Microchip Technology Inc.
Max.
1000
1000
1000
1000
1000
1000
1000
500
240
—
MSB
T
DATA
G
T
Acknowledge
ACK
T
Units
WTH
ms
ms
T
WTL
s
s
s
s
s
s
s
s
H