← Back to Patent Explorer
US4578751A Expired / Lapsed US ⏱️ 0.0 years remaining

System for simultaneously programming a number of EPROMs

Assignee: AT&T Inc
•
Filing: 1982-06-25
•
Granted: 1986-03-25
•
Expires: 2002-06-25
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method and system are used for simultaneously programming a group of erasable programmable read only memories (EPROMs) (11) originally set in the "all-ones" state, by routing (17-49) programmed bytes, bit by bit, to each memory site on each EPROM and blocking (48) or bypassing the programming steps where a programmed byte consists of all ones, thus saving the programming time that would be normally used to program "all-ones" sites. Each programmed site and the sites set in the "all-ones" state are verified (52) prior to the routing of subsequent programmed bytes.

Inventors

  • 👤 Edward A. Erwin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 20:16
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/10; G11C16/102

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 238 words
A system for simultaneously programming a plurality of erasable programmable read only memory devices (EPROMs), each having a number of memory sites that are each initially set in all-ones condition, which comprises: a central processing unit; means for rotating a program comprising a plurality of successive bytes from a master memory device and storing said program in said central processing unit; a cabinet rack for receiving multiple circuit boards each having several EPROMs, each having all of its memory sites set in the "all-ones" condition; an interface circuit interposed between said cabinet rack and said central processing unit for transmitting successive bytes comprising bits of ones and zeros to set each memory site accordingly and for subsequently reading the setting of each memory site back into said central processing unit; means within the central processing unit for transferring each byte of the program to said interface circuit for impression at successive memory sites; means within the central processing unit for recognizing bytes of all ones and blocking the impression of said "all-ones" bytes-bits to said interface; and means within the central processing unit for receiving through said interface circuit the byte setting of each programmed memory site and for verifying said setting with respect to the byte impressed through the interface circuit to the memory site, and for verifying the "all-ones" setting of those memory sites associated with the blocked "all-ones" byte recognized in the central processing unit.
Claim 2
Independent Claim 238 words
A system for simultaneously programming a plurality of erasable programmable read only memory devices (EPROMs), each having a number of memory sites that are each initially set in all-ones condition, which comprises: a central processing unit; means for rotating a program comprising a plurality of successive bytes from a master memory device and storing said program in said central processing unit; a cabinet rack for receiving multiple circuit boards each having several EPROMs, each having all of its memory sites set in the "all-ones" condition; an interface circuit interposed between said cabinet rack and said central processing unit for transmitting successive bytes comprising bits of ones and zeros to set each memory site accordingly and for subsequently reading the setting of each memory site back into said central processing unit; means within the central processing unit for transferring each byte of the program to said interface circuit for impression at successive memory sites; means within the central processing unit for recognizing bytes of all ones and blocking the impression of said "all-ones" bytes-bits to said interface; and means within the central processing unit for receiving through said interface circuit the byte setting of each programmed memory site and for verifying said setting with respect to the byte impressed through the interface circuit to the memory site, and for verifying the "all-ones" setting of those memory sites associated with the blocked "all-ones" byte recognized in the central processing unit.

References Cited (Backward Citations)

US3969618A Cited
US4093998A Cited
US4106105A Cited
US4244032A Cited
US4382279A Cited
US4443185A Cited
US4238839A Cited
US4498151A Cited
US4441164A Cited
US4377857A Cited
US4545038A Cited
US4460982A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-03-24 1989-09-23 1990-03-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-03-24 1993-09-23 1994-03-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-03-24 1997-09-23 1998-03-25 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag