Patent ID: 6686768
Filing Date: 2004-02-03
Classification: H01L,H03K

Abstract:
An electrically-programmable ladder network, having a first plurality of ladder control terminals and a second plurality of ladder rung or slave terminals, providing means whereby said slave terminals, and any circuitry connected thereto, may be electrically controlled through said control terminals;wherein said control terminals, being advantageously fewer than said slave terminals, yet comprise at least a first ground terminal and a second master terminal; wherein said ladder network has an initial, unprogrammed state; wherein said ladder network also has a sequence of different programmed ladder states, each state defined by a different one of said slave terminals, said slave terminal being dominated by said master terminal in said state; wherein said slave terminal, in said state, is the one programmably connected to said master terminal most recently, whereby said slave terminal is said to be dominated by said master terminal; wherein said slave terminal is not connected to said ground terminal in said state; wherein said ladder network may be programmably changed from each said state to the next, sequentially, in response to a plurality of predetermined ladder programming signals which may be transmitted to said ladder network through said ladder control terminals; wherein said ladder network further comprises:a plurality of composite programmable networks or C-nets, each individually and separately comprising: an antifuse-like programmable network or A-net, itself individually and separately comprising: a plurality of A-net terminals including at least first and second A-net terminals, through which said programming signals may be transmitted to said A-net; wherein said first and second A-net terminals are not electrically connected together through said A-net prior to programming of said A-net; and a first passive electrically-programmable means, responsive to ones of said programming signals, whereby at least said first and second A-net terminals may be electrically connected to one another; and a fuse-like programmable network or B-net, itself individually and separately comprising: a plurality of B-net terminals including at least first and second B-net terminals, through which said programming signals may be transmitted to said B-net; wherein said first and second B-net terminals are electrically connected together through said B-net prior to programming of said B-net; and a second passive programmable means, responsive to ones of said programming signals, whereby at least said first and second B-net terminals may be electrically disconnected from each other; wherein said second A-net terminal is connected to said second B-net terminal; wherein said C-nets are linked together sequentially, forming a C-net chain; wherein said C-net chain has a first end comprising said first A-net terminal of a first of said C-nets; wherein the first A-net terminal of each successive C-net in said C-net chain is connected to the second A-net terminal of the preceding C-net; and wherein said C-net chain has a second end comprising said second A-net terminal of a last of said C-nets; wherein the first B-net terminal of each C-net in said C-net chain is connected to said ground terminal; wherein said master terminal comprises said first end of said C-net chain; and wherein said plurality of slave terminals comprises the second B-net terminal of each C-net in said C-net chain; whereby in each said programmed ladder state, a plurality of ladder non-programming signals, to which said ladder network is unresponsive in said state, may be freely transmitted through said master terminal to its dominated slave terminal, and thereby to said circuitry connected thereto.