hcs500 Microchip Technology Inc., hcs500 Datasheet - Page 10

• Manufacturer Part Number: hcs500
• Description: Keeloq Code Hopping Decoder
• Manufacturer: Microchip Technology Inc.

HCS500
4.2.3
The command activation time (Table 4-1) is defined as
the maximum time the microcontroller has to wait for a
response from the decoder. The decoder will abort and
service the command request. The response time
depends on the state of the decoder when the Com-
mand mode is requested.
TABLE 4-1:
*
TABLE 4-2:
DS40153C-page 10
While receiving transmissions
During the validation of a received transmission
During the update of the sync counters
During learn
READ
WRITE
ACTIVATE_LRN
ERASE_ALL
PROGRAM
These parameters are characterized but not tested.
Instruction
COMMAND ACTIVATION TIMES
Decoder State
COMMAND ACTIVATION TIMES
DECODER COMMANDS
Command Byte
D2
C3
F0
E1
B4
16
16
16
16
16
Min
—
—
—
—
4.2.4
The command byte specifies the operation required by
the controlling microcontroller. Table 4-2 lists the com-
mands.
Read a byte from user EEPROM
Write a byte to user EEPROM
Activate a learn sequence on the decoder
Activate an erase all function on the decoder
Program manufacturer’s code and configuration byte
DECODER COMMANDS
2.5 ms BPW
3 ms
40 ms
170 ms
Operation
2002 Microchip Technology Inc.
MAX
Max
= 2.7 ms