nm95hs02 National Semiconductor Corporation, nm95hs02 Datasheet - Page 17

• Manufacturer Part Number: nm95hs02
• Description: Hisec-tm High Security Rolling Code Generator
• Manufacturer: National Semiconductor Corporation

Upon power-up the NM95HS01 02 CKI input must be
clocked a minimum of 1500 times to ensure the part is ready
for programming This allows the internal state machines
Programming the NM95HS01 02
The NM95HS01 02 HiSeC Generator uses four pins to read
and write the 13 bytes of on-chip EEPROM These are the
Key1 (K1) Key2 (K2) TX and CKI pins K1 functions as the
chip select line K2 functions as the data strobe CKI serves
as the serial clock and TX acts as the data out pin
Three voltage levels are required to program the device
Supervoltage (V
(0V) Supervoltage is used to select Read and Write modes
in the device These modes can only be entered by applying
supervoltage to K1 and K2 This alleviates the risk of the
device entering these modes during normal operation
The programming protocol for the NM95HS01 02 on-chip
EEPROM array was designed to match National Semicon-
ductor’s MICROWIRE format closely However there are
several differences One is the need to use a supervoltage
to select modes Another concerns the CKI clock input
and registers to perform their necessary power-on se-
quences (See Table VII )
Write Mode
The NM95HS01 02 HiSeC Generator can be placed in
Write mode when supervoltage is applied to both K1 and K2
in a specific sequence Upon power-up both K1 and K2
must be set to V
Programmer Support for NM95HS01 02
Worldwide third party support is provided by
Xeltek
National Semiconductor
System General
Hi-Lo ALL-07
National Semiconductor
SuperPro-EM
Universal
Programmer
NM95HS-PRO-X
Turpro-1 Univeral
Device Programmer
Evalutation kit support for NM95HS01 02 A demonstration kit for the
HiSeC High Security Rolling Code Generator is available
NM95HSEV
NM95HSPRO
Vendor
SV
) Read Write voltage (V
RW
and a minimum of 1500 clock
Europe 49-5722-203-125 (Germany)
America 408-524-1929
Asia 65-296-6433 (Singapore)
BBS 408-245-7082
Americas 800-272-9959
Switzerland 31-921-7844
America 408-263-6667 800-967-4776
Taiwan 886-2-917-3015
BBS 408-262-6438
Asia 886-2764-0215
America 510-623-3850
HiSeC Evaluation Board
HiSeC Single Site Programmer
RW
) and Ground
Contact Number
17
pulses applied to CKI to initialize the part (See Timing Dia-
gram on pg 16 ) After this initialization K2 is brought to
supervoltage K1 is then brought to supervoltage Now K2 is
brought back to V
NM95HS01 02 is now in Write mode
To program the first byte set K1 back to supervoltage and
place the first byte of data (V
(starting with the Least Significant Bit) As each bit is placed
on K2 clock the CKI pin to latch the bit When all bits of the
first byte have been latched in set K1 to V
TX output pin for a logic low
NM95HS01 02 has written the byte to memory Repeat this
sequence to program the remainder of the bytes When all
13 bytes have been programmed set K1 and K2 to 0V to
end Write mode
Read Mode
The NM95HS01 02 HiSeC Generator can be placed in
Read mode by applying supervoltage to K1 Upon power-
up both K1 and K2 must be set to V
1500 clock pulses applied to CKI to initialize the part (See
Timing Diagram on pg 16 ) After this initialization K1 is
brought to supervoltage Then K1 is brought back to V
The NM95HS01 02 is now in Read mode
To read the first byte set K1 back to supervoltage and
clock the CKI pin 8 times while polling TX EEPROM data is
sent Most Significant Bit first Continue clocking CKI to read
the remainder of the bytes When all 13 bytes have been
read set K1 back to V
mode
RW
RW
then K1 is brought back to V
Set K1 and K2 to 0V to end Read
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and V
RW
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