33
5
E
2
Key™ Function
The ROCKY-548TX provides an outstanding E
2
KEY™ function for
system integrator. Based on the E
2
KEY™ you could free to store the
ID Code, Pass Word, or Critical Data in the 1Kbit EEPROM.
Because the EEPROM is nonvolatile memory, you don’t have to
worry the losing of the very important data.
Basically the E
2
KEY™ is based on a 1Kbit EEPROM which is
configured to 64 words(from 0 to 63). You could access(read or
write) each word at any time.
When you start to use the E
2
KEY™ you should have the utility in the
package. The software utility will include four files as follows,
README.DOC
E2KEY.OBJ
EKEYDEMO.C
EKEYDEMO.EXE.
The E2KEY.OBJ provides two library function for user to integrate
their application with E
2
KEY™ function. These library
(read_e2key
and write_e2key)
are written and compiled in C format. Please
check the following statement, then you will know how to implement it
easily.
unsigned int read_e2key(unsigned int address)
/* This function will return the E
2
KEY™’s data at address. The
address range is from 0 to 63. Return data is one word,16 bits */
34
void write_e2key(unsigned int address,unsigned data)
/* This function will write the given data to E
2
KEY™ at address. The
address range is from 0 to 63. The data value is from 0 to 0xffff. */
To easy start to use the function, please refer the include
EKEYDEMO.C code at first.
Please note the E
2
KEY™ function is based on the working of parallel
port. So you should enable the ROCKY-548TX’s parallel port,
otherwise will be not working.
Appendix A. Watch-Dog Timer
