HCS201 Datasheet, PDF (20/28 Pages) Microchip Technology – KEELOQ Code Hopping Encoder

HCS201
FIGURE 8-3:
CODE WORD FORMAT: PREAMBLE/HEADER PORTION
P1
P12
Bit 0 Bit 1
23 TE 50% Duty Cycle Preamble
10 TE Header
Data Bits
FIGURE 8-4:
CODE WORD FORMAT: DATA PORTION (XSER=0)
Serial Number
Button Code
Status
LSB
MSB LSB
MSB S3 S0 S1 S2 VLOW RPT
Bit 0 Bit 1 Bit 30 Bit 31 Bit 32 Bit 33 Bit 58 Bit 59 Bit 60 _{Bit 61} Bit 62 Bit 63 Bit 64 Bit 65
Header Encrypted Portion
Fixed Portion
Guard
Time
TABLE 8-4: CODE WORD TRANSMISSION TIMING REQUIREMENTS
VDD = +3.5 to 6.0V
Commercial (C): Tamb = 0°C to +70°C
Industrial (I): Tamb = -40°C to +85°C
Code Words Transmitted
All
1 out of 2
Symbol
Characteristic
Number
of TE
Min.
Typ. Max.
Min.
TE Basic pulse element
1
360 400 440 180
TBP PWM bit pulse width
3
1.08 1.2 1.32 0.54
TP Preamble duration
23
8.64 9.2 10.56 4.32
TH Header duration
10
3.6 4.0 4.4
1.8
THOP Hopping code duration
96
34.56 38.4 42.24 17.28
TFIX Fixed code duration
102
36.72 40.8 44.88 18.36
TG Guard Time
39
14.04 15.6 17.16 7.02
 Total Transmit Time
271
97.56 108.4 119.24 48.78
 PWM data rate

925 833 757 1851
Note 1: The timing parameters are not tested but derived from the oscillator clock.
Typ.
200
0.6
4.6
2.0
19.2
20.4
7.8
54.2
1667
Max.
220
0.66
5.28
2.2
21.12
22.44
8.58
59.62
1515
Units
µs
ms
ms
ms
ms
ms
ms
ms
bps
DS41098C-page 20
© 2001 Microchip Technology Inc.