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Early/Late Personalize Common Architecture

IP.com Disclosure Number: IPCOM000123703D
Original Publication Date: 1999-Mar-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Asano, T: AUTHOR [+3]

Abstract

Disclosed is the circuit design technique to improve the productivity of ROM design process. Mask ROM is categorized Early Perso and Late Perso depend on which of the mask process is used to program "1" and "0". "RX" is a mask of early stage of semiconductor process. So, a personalization by RX is early perso ROM. The cell is small but is long turn-around-time to manufacture new personalization ROM. "CA" is a mask to make contact which is late phase of semiconductor process. The personalization by "CA" is late perso ROM. The cell is large but is short turn-around-time to manufacture new personalization ROM.

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Early/Late Personalize Common Architecture

   Disclosed is the circuit design technique to improve the
productivity of ROM design process.  Mask ROM is categorized Early
Perso and Late Perso depend on which of the mask process is used to
program "1" and "0".  "RX" is a mask of early stage of semiconductor
process.  So, a personalization by RX is early perso ROM.  The cell
is small but is long turn-around-time to manufacture new
personalization ROM.  "CA" is a mask to make contact which is late
phase of semiconductor process.  The personalization by "CA" is late
perso ROM.  The cell is large but is short turn-around-time to
manufacture new personalization ROM.

   Fig.1 is the proposed cell layout of "RX" and "CA"
ROM.  In the layout, BIT line is physically common for the both
cells.  And, the Cell size along WORD Line direction is common for
the both cells.  Since bit line contact can be shared by the two
cells in "RX" cell, the cell size along BIT line can be smaller in
"RX" cell.  So,the WORD pitch becomes different.  "RX" cell is
smaller than "CA" cell because of the above reason.

   By defining the cell layout as above, other circuits of
"RX" and "CA" personalization ROM can be the same as well.  The
difference is only on the layout of the cell itself and the pitch of
Local Word Decode circuit.  Once the circuit is designed, both "RX"
and "CA" personalization ROM can be available immediately.

   From user's point of view, the usage of "RX" and "CA"
p...