HCS473-I/SL Microchip Technology, HCS473-I/SL Datasheet - Page 26

• Manufacturer Part Number: HCS473-I/SL
• Description: IC KEELOQ 3AXIS TRANSCODR 14SOIC
• Manufacturer: Microchip Technology
• Series: KEELOQ®r
• Type: Code Hopping Encoder and Transponderr

Specifications of HCS473-I/SL

• Applications: Access Control Systems
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

HCS473
3.2.3.1
The SELECT TRANSPONDER sequence must imme-
diately follow the HCS473 wake-up. A 12-bit Vehicle ID
(VID) follows the 3-bit command. The 4-bit Token ID
(TID) is sent by pulsing the field to identify which tran-
sponder should respond.
The HCS473 counts each time the field is pulsed (6
LF
0. If the VID matched, the HCS473 will send an
Acknowledge when the TID matches the counter. Any
further TID pulses after the Acknowledge occurs will
deselect the device, putting it back to SLEEP - again
requires a wake-up sequence to communicate.
FIGURE 3-12:
DS40035C-page 24
Inductive In
RF Response
TE
(LC Pins)
(DATA Pin)
period), the first pulse setting the counter equal to
SELECT TRANSPONDER
T
SF
WAKE ACK
ACK
TRANSPONDER SELECT SEQUENCE (RF RESPONSE EXAMPLE)
T
CMD
16-bit Device Identifier
Command
T
CMD
T
CMD
DID
‘000
CMD
12-Bit
VID
2
’
Preliminary
12 bits
VID
=
TID=0
6 LF
TE
[ 12-bit Vehicle ID ] [ 4-bit Token ID ]
Pulses
1-16
TID
TID=1 TID=2 TID=3
Any HCS473 that did not match both the presented VID
and TID will return to SLEEP, unselected, remaining
that way until the next wake-up pulse occurs.
The next command must begin T
Acknowledge. If the LC input is high a point T
after the Acknowledge ends, the HCS473 will return to
SLEEP, unselected, assuming the transponder reader
is sending additional TID pulse(s) to select a different
device. A device of any TID value may therefore be
uniquely selected, regardless if a device with lower TID
has already acknowledged.
Transponder Select ACK
5 LF
Example for TID=’0011’
VID
ACK
TE
T
TSCMD
T
TSACK
T
TID
TSCMD
‘XXX’
CMD
 2002 Microchip Technology Inc.
Command
Next
TSCMD
after the
TSCMD
MIN