HCS365_11 Datasheet, PDF (7/40 Pages) Microchip Technology – KEELOQ® Code Hopping Encoder Crypt keys are read protected

FIGURE 2-2: I/O CIRCUITS
Figure 2-2(A)
S0, S1, S2
Inputs
ZIN
Figure 2-2(B)
DATA I/O
VDD
PFET
DATA OUT
NFET
Figure 2-2(C)
DATA, RFEN
STEP
Outputs
VDD
P
N
HCS365
FIGURE 2-3: BASIC FLOW DIAGRAM OF
THE DEVICE OPERATION
START
Sample Buttons
Get Config
Seed
Yes
TX?
No
Increment
Counter
Read
Seed
Encrypt
Transmit
Time-
Yes
Out
No
No
MTX
STOP
Yes
No
Buttons
Yes
No
Seed ^Yes Seed
Yes
Time
Button
No
No
No
New
Buttons
Yes
© 2011 Microchip Technology Inc.
DS41109E-page 7