Data processor having operating modes selected by at least one m

Details Data processor having operating modes selected by at least one m Data processor having operating modes selected by at least one m

1994-10-17

1997-01-28

Black, Thomas G.

Boots, shoes, and leggings

395180, 395750, 364DIG1, 364DIG2, 364707, G06F 1216

Patent

active

055985696

ABSTRACT:
A data processor (20) includes a nonvolatile memory system (25) which stores not only normal program memory (31), but also mask option bits (32), within a common array (30) of nonvolatile memory cells. A control circuit (40) of the nonvolatile memory system (25) detects when a central processing unit (21) is accessing the program memory (31). In response to either an end of reset signal or a refresh request signal, the control circuit (40) copies the mask option bits (32) into a volatile mask option register (44) only when the central processing unit (21) is not accessing the program memory (31). Otherwise, the control circuit (40) holds off the access to the mask option bits (32). The mask option register (44) provides signals to various circuits (28) to control their operation. Thus, the mask option bits (32) may be stored in nonvolatile form in the same array (30) as the program memory (31), enhancing reliability and reducing integrated circuit size.

REFERENCES:
patent: 4084235 (1978-04-01), Hirtle et al.
patent: 4124891 (1978-11-01), Weller, III et al.
patent: 4344127 (1982-08-01), McDaniel et al.
patent: 4580216 (1986-04-01), Bellay et al.
patent: 4794558 (1988-12-01), Thompson
patent: 4807189 (1989-02-01), Pinkham et al.
patent: 4817058 (1989-03-01), Pinkham
patent: 4899310 (1990-02-01), Baba et al.
patent: 5134699 (1992-07-01), Aria et al.
patent: 5247682 (1993-09-01), Kondou et al.
patent: 5261049 (1993-11-01), Lumelsky et al.
patent: 5261104 (1993-11-01), Bertram et al.
patent: 5319606 (1994-06-01), Bowen et al.
patent: 5333287 (1994-07-01), Buerkle et al.
patent: 5384745 (1995-01-01), Konishi et al.
patent: 5406064 (1995-04-01), Takahashi
patent: 5428748 (1995-06-01), Davidson et al.
patent: 5528535 (1996-06-01), Honjo et al.
Motorola, Inc.; "Motorola System Product Technical Data, Advance Information 8-Bit Microcomputers: MC6805S2, MC6805S3, MC68705S3"; 1986; p. 5.
Motorola, Inc.; Advance Information, "MC68(7)05P Series 8-Bit Microcomputers"; Oct. 1984; pp. 9-1 through 9-6.
Motorola, Inc.; Advance Information, "MC68(7)05R/U Series 8-Bit Microcomputers"; Jan. 1984; pp. 9-1 through 9-6.
Motorola, Inc.; "HC08-MC68HC708XL36 Technical Summary;"1993; pp. 2-8 through 2-9.

Affiliated with

Also associated with

Rating

Data processor having operating modes selected by at least one m does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Data processor having operating modes selected by at least one m, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data processor having operating modes selected by at least one m will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-948010