Electronic digital logic circuitry – Interface – Current driving
Patent
1995-12-01
1997-09-09
Hudspeth, David R.
Electronic digital logic circuitry
Interface
Current driving
326 45, 326 50, 326 56, H03K 190175, H03K 19094
Patent
active
056660715
ABSTRACT:
An integrated circuit incorporating programmable pullup and pulldown devices into each input/output (I/O) pad is described. Each I/O pad may be individually programmed to include a pullup or pulldown function. Pullup and pulldown resistors may be removed from a system employing the present integrated circuit. Programming of the I/O pads may be accomplished in a number of ways. Following the deassertion of a reset signal, high impedance states may be transferred into a shift data storage within the integrated circuit. Once the states are received, they are shifted to the respective I/O pads through a serial chain connection of the pullup and pulldown devices within each I/O pad. The states are then maintained by each pullup and pulldown device until a subsequent reprogramming. Software programs may also reprogram the pullup and pulldown states by storing appropriate values into the shift data storage. The program then sets an appropriate value into a status register included within the integrated circuit. Upon detection of the value within the status register, the integrated circuit reprograms the high impedance states of the I/O pads with the states stored in the shift data storage.
REFERENCES:
patent: 4071904 (1978-01-01), Miller
patent: 4779229 (1988-10-01), Agrawal
patent: 4940909 (1990-07-01), Mulder et al.
patent: 5087840 (1992-02-01), Davies et al.
patent: 5115191 (1992-05-01), Yoshimori
patent: 5151621 (1992-09-01), Goto
patent: 5391940 (1995-02-01), Linn
patent: 5402014 (1995-03-01), Ziklik et al.
patent: 5410267 (1995-04-01), Haycock et al.
IBM Technical Disclosure Bulletin entitled "Loading Test Patterns Into Complex Semiconductor Chips Using Isolated Outboard Level Sensitive Scan Design Chains", vol. 29, No. 3, Aug. 1986, New York, U.S.A., XP002016050, p. 1202-1203.
Hawkins Keith G.
Javalagi Shivachandra I.
Nair Harikumar B.
Advanced Micro Devices , Inc.
Daffer Kevin L.
Hudspeth David R.
Roseen Richard
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