HCS300/SN Microchip Technology, HCS300/SN Datasheet - Page 9

• Manufacturer Part Number: HCS300/SN
• Description: IC CODE HOPP ENCODR 15FUNC 8SOIC
• Manufacturer: Microchip Technology
• Type: Code Hopping Encoderr

Specifications of HCS300/SN

• Mounting Type: Surface Mount
• Applications: Remote Secure Access, Keyless Entry
• Package / Case: 8-SOIC (3.9mm Width)
• Ic Function: Encoder IC
• Supply Voltage Range: 2V To 6.3V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: SOIC
• No. Of Pins: 8
• Termination Type: SMD
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Leaded Process Compatible: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.3
Synchronous Transmission mode can be used to clock
the code word out using an external clock.
To enter Synchronous Transmission mode, the Pro-
gramming mode start-up sequence must be executed
as shown in Figure 4-3. If either S1 or S0 is set on the
falling edge of S2 (or S3), the device enters Synchro-
nous Transmission mode. In this mode, it functions as
a normal transmitter, with the exception that the timing
of the PWM data string is controlled externally and 16
extra bits are transmitted at the end with the code word.
FIGURE 4-3:
FIGURE 4-4:
MSb
2001 Microchip Technology Inc.
PWM
S2
S[1:0]
Reserved
(16 bits)
Synchronous Transmission Mode
T
PS
T
PH
Padding
(2 bits)
1 T
SYNCHRONOUS TRANSMISSION MODE
CODE WORD ORGANIZATION (SYNCHRONOUS TRANSMISSION MODE)
PH
“01,10,11”
2
S2 S1 S0 S3
Fixed Portion
Button
Status
t = 50ms
Serial Number
(28 bits)
The button code will be the S0, S1 value at the falling
edge of S2 or S3. The timing of the PWM data string is
controlled by supplying a clock on S2 or S3 and should
not exceed 20 kHz. The code word is the same as in
PWM mode with 16 reserved bits at the end of the
word. The reserved bits can be ignored. When in Syn-
chronous Transmission mode S2 or S3 should not be
toggled until all internal processing has been com-
pleted as shown in Figure 4-4.
Preamble
S2 S1 S0 S3
Button
Status
Header
Encrypted Portion
DISC+ OVR
(12 bits)
82 Data bits
Transmitted
LSb first.
HCS300
Sync Counter
DS21137F-page 9
(16 bits)
Data
LSb