HCS500-ISM MICROCHIP [Microchip Technology], HCS500-ISM Datasheet - Page 9

• Manufacturer Part Number: HCS500-ISM
• Description: KEELOQ CODE HOPPING ENCODER
• Manufacturer: MICROCHIP [Microchip Technology]

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:
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
1997 Microchip Technology Inc.
COMMAND ACTIVATION TIMES
Instruction
Decoder State
COMMAND ACTIVATION TIMES
DECODER COMMANDS
Command Byte
E1
D2
C3
B4
F0
16
16
16
16
16
Preliminary
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
170 ms
2 1/2 BPW
3 ms
40 ms
Operation
MAX
= 2.7 ms
Max
HCS500
DS40153B-page 9