HCS515-I/P Microchip Technology, HCS515-I/P Datasheet - Page 8

• Manufacturer Part Number: HCS515-I/P
• Description: IC,Remote-Control Receiver/Decoder,CMOS,DIP,14PIN
• Manufacturer: Microchip Technology
• Type: Code Hopping Decoderr

Specifications of HCS515-I/P

• Applications: Remote Secure Access, Keyless Entry
• Mounting Type: Through Hole
• Package / Case: 14-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

HCS515
4.0
The HCS515 interfaces to a microcontroller via a syn-
chronous serial interface. A clock and data line are
used to communicate with the HCS515. The microcon-
troller controls the clock line. There are two groups of
data transfer messages. The first is from the decoder
whenever the decoder receives a valid transmission.
The decoder signals reception of a valid code by taking
the data line high (maximum of 500 ms) The microcon-
troller then services the request by clocking out a data
string from the decoder. The data string contains the
function code, the status bit, and block indicators. The
second is from the controlling microcontroller to the
decoder in the form of a defined command set.
Figure 4-1 shows the HCS515 decoder and the I/O
interface lines necessary to interface to a microcontrol-
ler.
4.1
The decoder informs the microcontroller of a valid
transmission by taking the data line high for up to
500 ms. The controlling microcontroller must acknowl-
FIGURE 4-1:
FIGURE 4-2:
DS40183D-page 8
S_CLK
S_DAT
A
INTERFACING TO A
MICROCONTROLLER
Valid Transmission Message
Decoder Signal Valid
V
T
CC
CLA
Transmission
T
DHI
T
ACK
HCS515 DECODER AND I/O INTERFACE LINES
DECODER VALID TRANSMISSION MESSAGE
T
CLKH
X
X
X
T
ACT
1
2
3
4
5
6
7
B
0
NC
NC
V
S1
S0
MCLR
NC
DD
REPT V
HCS515
T
CLKL
LOW
S0
S_CLK
S_DAT
T
RF_IN
CLKH
S1
V
NC
NC
NC
SS
S2
14
13
12
11
10
9
8
Information
S3
X
X
X
T
DS
1
edge by taking the clock line high. The decoder then
takes the data line low. The microcontroller can then
begin clocking a data stream out of the HCS515. The
data stream consists of:
• START bit ‘
• 2 status bits [
• 4-bit function code [
• STOP bit ‘
• 4 bits indicating the number of transmitters
• 4 bits indicating which block was used
• 64 bits of the received transmission with the hop-
The decoder will terminate the transmission of the data
stream at any point where the clock is kept low for
longer than 1 ms. Therefore, the microcontroller can
only clock out the required bits. A maximum of 80 bits
can be clocked out of the decoder.
CNT0
learned into the decoder [
[
ping code decrypted.
Note:
TX3…TX0
CNT3
Data is always clocked in/out Least
Significant bit (LSb) first.
1
].
0
’.
TX0
’.
REPEAT
S3 S2 S1 S0
TX3
,
MICRO RESET
Ci
Vlow
SYNC CLOCK
2002 Microchip Technology Inc.
SYNC DATA
S0 OUTPUT
S1 OUTPUT
RX0
CNT3…CNT0
RF DATA
Received String
].
RX1
].
RX62
].
RX63
Cii