HCS515-IP Microchip Technology, HCS515-IP Datasheet - Page 14

• Manufacturer Part Number: HCS515-IP
• Description: KEELOQ CODE HOPPING DECODER
• Manufacturer: Microchip Technology

HCS515
5.0
The memory is divided between system memory that stores the transmitter information (read protected) and user mem-
ory (read/write). Commands to access the user memory are described in Sections 4.2.5 and 4.2.6.
The following information stored in system memory needs to be programmed before the decoder can be used:
• 64-bit manufacturer’s code
• Decoder configuration byte
5.1
The decoder is configured during initialization by setting the appropriate bits in the configuration byte. The following table
list the options:
5.1.1
LRN_MODE selects between two learning modes. With LRN_MODE = 0, the normal (serial number derived) mode is
selected; with LRN_MODE=1, the secure (seed derived) mode is selected. See Section 6.0 for more detail on learning
modes.
5.1.2
The HCS515 can be configured to indicate repeated transmissions. In a stand-alone configuration, repeated transmis-
sions must be disabled.
DS40183A-page 14
Note 1: These memory locations are read protected and can only be written to using the program command with
Bit
0
1
2
3
4
5
6
7
2: The contents of the system memory is encrypted by a unique 64-bit key that is stored in the HCS515. To
DECODER PROGRAMMING
Configuration Byte
LRN_MODE
REPEAT
the device powered up.
initialize the system memory, the HCS515’s program command must be used.
LRN_MODE
Mnemonic
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
REPEAT
Learning mode selection
Reserved
Repeat Transmission enable
Reserved
Reserved
Reserved
Reserved
Reserved
LRN_MODE = 0—Normal Learn
LRN_MODE = 1—Secure Learn
0 = Disable
1 = Enabled
Preliminary
Description
1998 Microchip Technology Inc.