Miscellaneous active electrical nonlinear devices – circuits – and – Specific signal discriminating without subsequent control – By phase
Patent
1993-06-30
1996-02-20
Callahan, Timothy P.
Miscellaneous active electrical nonlinear devices, circuits, and
Specific signal discriminating without subsequent control
By phase
327142, 327163, 327198, H03K 522
Patent
active
054932424
ABSTRACT:
A single bit status register includes an input flip-flop, an asynchronous latch having an input coupled to an output of the input flip-flop, a comparator for comparing the outputs of the flip-flop and the latch, and an output stage which provides an error output when the comparator determines that the outputs of the flip-flop and the latch are not the same. In this fashion, it is known when a "read" of the status register is invalid due to the presence of the error output. Preferably, the register also includes a reset disabling mechanism which prevents the input flip-flop from being reset until a valid read has occurred. A n-bit status register includes n register sections, where each register section includes an input flip-flop, an asynchronous latch having an input coupled to an output of the input flip-flop, and a register section comparison mechanism for comparing the outputs of the flip-flop and the latch in that register section. The method of the present invention includes the steps of: a) capturing a status bit in an input flip; b) latching the status bit into an output latch; c) asynchronously enabling the output latch; d) comparing the outputs of the flip-flop and the latch; e) outputting an error signal if the outputs of the flip-flop and the latch are different; and f) outputting the status bit at least if the output of the flip-flop and the latch are the same.
REFERENCES:
patent: 3555255 (1971-01-01), Toy
patent: 3714463 (1973-01-01), Laune
patent: 3950705 (1976-04-01), Fuerherm
patent: 4700084 (1987-10-01), Honaker, Jr.
patent: 4876701 (1989-10-01), Sanner
patent: 4999528 (1991-03-01), Keech
patent: 5038059 (1991-08-01), Ebzery et al.
patent: 5233617 (1993-08-01), Simmons et al.
patent: 5264802 (1993-11-01), Beg et al.
patent: 5266851 (1993-11-01), Nukui
`Microelectronics` publication, McGraw-Hill (Millman et al): Articles on bistable latches and various type Flip-Flops, 1987.
`Microcomputer Interfacing` publication, Addison-Wesley (Stone): Article on asynchronous timing difficulties, Feb. 1983.
Simmons Laura E.
Thomsen Joseph A.
Callahan Timothy P.
Nu Ton My-Trang
VLSI Technology Inc.
LandOfFree
Status register with asynchronous read and reset and method for does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Status register with asynchronous read and reset and method for , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Status register with asynchronous read and reset and method for will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1358408