HCS515-IP Microchip Technology, HCS515-IP Datasheet - Page 15

• Manufacturer Part Number: HCS515-IP
• Description: KEELOQ CODE HOPPING DECODER
• Manufacturer: Microchip Technology

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:
1998 Microchip Technology Inc.
DECODER DATA
C DATA
Programming Waveform
CLK
A
Start Command
PROGRAMMING WAVEFORM
T
T
PP
PP
1
2
T
T
PP
PP
3
4
B
LSB
T
CLKL
Command Byte
T
CLKH
MSB
T
T
CMD
DS
C
LSB
Configuration Byte
Preliminary
MSB
T
ADDR
D
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
T
DATA
Programming Data String
E
F
LSB
Most Significant Byte
MSB
T
HCS515
DATA
G
DS40183A-page 15
Acknowledge
T
ACK
T
WT 2
T
AW
H