THE REFRESHMENT OF RAM FOR PASSWORD CIRCUIT IN SUPPORT CHIP SECURE EEPROM
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-Jun-05
In one currently designed support chip, one part of the password circuit is a six-byte RAM that receives and holds a six-byte password which is transferred from the configuration EEPROM during Power-On-Reset. It is the password from the RAM, not from the configuration EEPROM, that is used to compare with the one entered from the outside device via an on-chip slave SPI. With the current application of the support chip in a pager receiver which rarely fbrces the Power-On-Reset after it is first cold-started with a new battery (only the receiver part of the pager is turned off and on), there is always a risk of losing data in RAM due to ESD.