HCS500-IP Microchip Technology, HCS500-IP Datasheet - Page 15

• Manufacturer Part Number: HCS500-IP
• Description: KEELOQ CODE HOPPING ENCODER
• 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)
FIGURE 5-1:
• Activation and Acknowledge Sequence (G to H)
1997 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 key. After completion of the programming
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, programming also fails.
MSB
T
DATA
Programming Data String
E
F
LSB
Most Significant Byte
MSB
T
HCS500
DATA
G
DS40153B-page 15
Acknowledge
T
ACK
T
WT 2
T
AW
H