HCS360-/P MICROCHIP [Microchip Technology], HCS360-/P Datasheet - Page 15

• Manufacturer Part Number: HCS360-/P
• Manufacturer: MICROCHIP [Microchip Technology]

6.0
When using the HCS360 in a system, the user will have
to program some parameters into the device including
the serial number and the secret key before it can be
used. The programming
192 bits in a serial data stream, which are then stored
internally in EEPROM. Programming will be initiated by
forcing the PWM line high, after the S3 line has been
held high for the appropriate length of time. S0 should
be held low during the entire program cycle. The S1
line on the HCS360 part needs to be set or cleared
depending on the LS bit of the memory map (Key 0)
before the key is clocked in to the HCS360. S1 must
remain at this level for the duration of the programming
cycle. The device can then be programmed by clocking
in 16 bits at a time, followed by the word’s complement
FIGURE 6-1:
FIGURE 6-2:
 2001 Microchip Technology Inc.
(Clock)
S2/S3
(Data)
PWM
Enter Program
S1
The V
Note 1: Unused button inputs to be held to ground during the entire programming sequence.
(Clock)
S2/S3
(Data)
PWM
Mode
PROGRAMMING THE HCS360
S1
Programming Cycle
DD
2: The V
Note: If a Verify operation is to be done, then it must immediately follow the Program cycle.
Bit190
T
pin must be taken to ground after a program/verify cycle.
2
T
End of
Bit191
PROGRAMMING WAVEFORMS
VERIFY WAVEFORMS
1
DD
T
Bit 0
Bit 0
pin must be taken to ground after a program/verify cycle.
T
WC
CLKL
allows the user to input all
Bit 1
T
Begin Verify Cycle Here
Bit 2
DS
T
Bit 3
DH
Data for Word 0 (KEY_0)
Bit 0
Repeat for each word
Bit 14 Bit 15
T
Bit 1 Bit 2
CLKH
T
DV
Bit 0
Bit 3
Data in Word 0
Bit 1 Bit 2
using S3 or S2 as the clock line and PWM as the data
in line. After each 16-bit word is loaded, a programming
delay is required for the internal program cycle to com-
plete. The acknowledge can read back after the pro-
gramming delay (T
complement have been downloaded, an automatic
bulk write is performed. This delay can take up to Twc.
At the end of the programming cycle, the device can be
verified (Figure 6-1) by reading back the EEPROM.
Reading is done by clocking the S3 line and reading the
data bits on PWM. For security reasons, it is not possi-
ble to execute a verify function without first program-
ming the EEPROM. A verify operation can only be
done once, immediately following the program
cycle.
Bit 14
Bit 3
Bit 15
Bit 14 Bit 15
WC
Bit 16 Bit 17
). After the first word and its
T
WC
Bit 16 Bit 17
Data for Word 1
HCS360
Acknowledge
DS40152D-page 15
Bit190 Bit191