Mark J Pedersen

US Patent:

56684924, Sep 16, 1997

Filed:

Mar 13, 1996

Appl. No.:

8/617968

Inventors:

Mark Eric Pedersen - Burlington VT
Peter Wohl - Williston VT

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03K 513
H03K 3289

US Classification:

327291

Abstract:

A globally distributed system clock is received and selectively gated by local clock generators responsive to global control signals. The local clock generators, which are located proximately to sequential circuits having serial scan paths, produce scan and functional clock signals adapted to the sequential circuits, which may have a variety of required timing diagrams.

US Patent:

56491506, Jul 15, 1997

Filed:

Apr 12, 1995

Appl. No.:

8/420962

Inventors:

Mark Eric Pedersen - Burlington VT

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1300
G06F 1100

US Classification:

395437

Abstract:

A scannable LIFO register stack in which registers are arranged in a stack with each register having a number of bit locations. Each register is in communication with an adjacent register located above and below it. In particular, each bit location in a register within the stack located between the top and the bottom register is in communication with a corresponding bit location in an adjacent register located above the register and a corresponding bit location in an adjacent register located below the register. Except for the last bit, each bit location in the top register has a connection to an offset bit location in the bottom register. Shifting a bit of data from a bit location in the top register to the offset bit location in the bottom register results in the bit being shifted to the right by one bit location according to the present invention. The last bit location in the top register has an output that is used as a scan output. The first bit location in the bottom register has an input used as a scan input.