MODULAR COMPUTER MEMORY CIRCUIT BOARD

DE-GLITCHABLE NON-METASTABLE FLIP-FLOP CIRCUIT

Title of the Invention DE-GLITCHABLE NON-METASTABLE FLIP-FLOP CIRCUIT The flip-flop circuit of the present invention is one that cannot glitch or enter a metastable hang-up state and has a probability of one of being completely settled at some given finite time following clocking. The flip-flop circuit is comprised of an input logic gate, an integrator and a logic latch circuit. In operation, the input logic gate changes state upon the coincidence of input signals,which change in state causes the integrator to change output level at a controlled rate. The latch circuit is sensitive to the output level of the integrator and changes state only when the integrator's output level reaches or exceeds preselected thresholds.

MODULAR COMPUTER MEMORY CIRCUIT BOARD

MODULAR COMPUTER MEMORY CIRCUIT BOARD A memory expansion board capable of holding up to 16 Mbytes of memory devices , using primarily 1 Mbit chips, in 2 Mbyte module increments, on a single IBM PC/AT compatible size board. The circuit board is so designed that when the memory expansion board is populated by modules and placed in a computer system it does not interfere with any of the other expansion slots within the computer system, all of the expansion slots being normally spaced apart. The memory expansion board also includes a means of protecting the memory expansion board and modules from damage due to misalignment when inserting the board and/or modules. When certain of the modules are inserted rotated 180 degrees the circuit board cannot be properly installed in the system board because of physical interference. Lastly, the memory expansion board includes a means for providing reduced length addressing memory lines to memory devices appearing on opposite sides of a circuit board.

Schaltungsplatte für modularen Rechnerspeicher

COMPUTER MEMORY CIRCUIT BOARD

PURPOSE: To avoid the constraint of memory amounts by adding a memory by using plural circuit boards outside a main system board. CONSTITUTION: A memory module 400 is connected with an extension board 300 by using two connectors 306. The large part of a circuit related with each module 400 is arranged on the extension board 300 for minimizing the size of the memory module 400, and an address control signal buffer 308 is attached between the connectors of each module. The control circuit of the memory module 400 is arranged on the extension board, so that the necessary size of the module 400 itself can be reduced. Moreover, a parity chip 314, module control circuit 310, and diagnostic circuit 312 which are generally used by an on- board memory 302 and the module 400 are arranged on the extension board 300. Thus, the effective memory of a system can be increased by adding the extension board 300, and the constraint of memory amounts can be avoided. COPYRIGHT: (C)1991,JPO ...