HCS410 Datasheet, PDF (22/36 Pages) Microchip Technology – KEELOQ CODE HOPPING ENCODER AND TRANSPONDER

HCS410
3.7.5 MTX3: MINIMUM CODE WORDS
COMPLETED
If this bit is set, the HCS410 will transmit a minimum of
3 words before it powers itself down. If this bit is
cleared, the HCS410 will only complete the current
transmission. This feature will only work if VDD is con-
nected directly to the battery as shown in Figure 2-1.
3.7.6 VLOW: LOW VOLTAGE TRIP POINT
The low voltage trip point select bit is used to tell the
HCS410 what Vdd level is being used. This information
will be used by the device to determine when to send
the voltage low signal to the receiver. When this bit is
set, the Vdd level is assumed to be operating from a 5
volt or 6 volt supply. If the bit is cleared, then the Vdd
level is assumed to be 3.0 volts. Refer to Figure 5-3 for
voltage trip point. When the battery reaches the Vlow
point, the LED will flash once for 200 ms on during a
code hopping transmission.
3.7.7 LED: OUTPUT ENABLE
If this bit is set, the S2 doubles as an LED output line.
If this bit is cleared (0), S2 is only used as an input.
3.7.8 TBSL: TRANSPONDER BAUD RATE
SELECT
This option selects the baud rate for IFF communica-
tion between a TE of 100 µs or 200 µs.
3.7.9 MANCH: MANCHESTER CODE
ENCODING
MANCH selects between Manchester code modulation
and PWM modulation in code hopping mode. If
MANCH = 1, Manchester code modulation is selected.
If MANCH is cleared, PWM modulation is selected.
3.7.10
ACOLI: ANTI-COLLISION
COMMUNICATION AND
XPRF: TRANSPONDER ECHOING
ON PWM OUTPUT
ACOLI = 1, XPRF = 0
If ACOLI is set the anti-collision operation during bi-
directional transponder mode (IFF) is enabled. This
feature is useful in situations where multiple transpon-
ders enter the magnetic field simultaneously.
ACOLI = 0, XPRF = 1
If XPRF is set, and ACOLI is cleared, proximity activa-
tion is enabled. the HCS410 starts sending out ACK
pulses when it detects a magnetic field. If the HCS410
doesn’t receive a start bit from the decoder within 50
ms of sending the first set of ACK pulses, the HCS410
will transmit a code hopping transmission on LC and
PWM pins for 2 seconds.
ACOLI = 1, XPRF = 1
If both the ACOLI and XPRF are set, all of the HCS410
transponder responses are echoed on the PWM out-
put, as described in Section 2.6.2.
3.7.11 DINC: DELAYED INCREMENT
If DINC is set to ‘1’, the delayed increment feature is
enabled. If DINC is cleared, the counter only incre-
ments once each time the button is pressed.
3.7.12 XSER: EXTENDED SERIAL NUMBER
If XSER is set, the full 64-bit SEED number is
transmitted. If XSER is cleared, the four most signifi-
cant bits of the serial number are substituted by
S[2:0] = S2:S1:S0: 0 and is compatible with the
HCS200/300/301.
DS40158C-page 22
Preliminary
© 1997 Microchip Technology Inc.