Semiconductor circuit with flash ROM and improved security...

Details Semiconductor circuit with flash ROM and improved security... Semiconductor circuit with flash ROM and improved security...

2006-06-06

2006-06-06

Beausoliel, Robert (Department: 2113)

Error detection/correction and fault detection/recovery

Data processing system error or fault handling

Reliability and availability

C726S027000

Reexamination Certificate

active

07058856

ABSTRACT:
This invention provides a micro controller in which a JTAG (Joint Test Action Group) port becomes available through a specific operation even after a security bit is set. More specifically, an embodiment of this invention provides a micro controller wherein: when an address signal AD2and data DT2are input from a JTAG port11, the address signal AD2and data DT2are kept in shift registers25and26through a TAP (Test Access Port)24; the address signal AD2is forwarded to a flash ROM and data DT1of the address specified by the address signal AD2is read out and output a comparator27; the data DT2is also output the comparator27; if the data DT1and DT2agree, the output signal from the comparator27turns “H” and the output signal from an AND gate23turns “L” independent of a security signal SEQ; and thereby a JTAG control circuit12is switched on and the JTAG port11becomes connected to TAPs13and14through the JTAG control circuit12.

REFERENCES:
patent: 4698750 (1987-10-01), Wilkie et al.
patent: 5689516 (1997-11-01), Mack et al.
patent: 5737760 (1998-04-01), Grimmer et al.
patent: 5819025 (1998-10-01), Williams
patent: 6145122 (2000-11-01), Miller et al.
patent: 6243842 (2001-06-01), Slezak et al.
patent: 6523099 (2003-02-01), Namekawa
patent: 6662314 (2003-12-01), Iwata et al.
patent: 6711684 (2004-03-01), Moroney et al.
patent: 6769065 (2004-07-01), Mayer
patent: 2005/0039039 (2005-02-01), Moyer et al.

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