Power Control and Status Circuitry for Communicating Power on Reset Control and Status Via a Single Electrode

• US 20090044034A1
• Filed: 08/08/2007
• Published: 02/12/2009
• Est. Priority Date: 08/08/2007
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Tagare, Madhavi, Wong, Kern
• Granted Patent: US 7,788,515 B2
• Time in Patent Office: Days
• US Class Current: 713/330
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C

Abstract

A system and method providing, via a single output electrode of an integrated circuit having internal circuitry, a status signal having time multiplexed states indicative of a power on reset condition for external circuitry following enablement of operations of portions of the internal circuitry, and further indicative of subsequent operation statuses of the internal circuitry portions.

Claims

1. An apparatus including an integrated circuit having internal circuitry for providing, via a single output electrode, a status signal having time multiplexed states indicative of a power on reset condition for external circuitry following enablement of operations of portions of said internal circuitry, and further indicative of subsequent operation statuses of said internal circuitry portions, comprising:

shorter delay circuitry responsive to a plurality of ready signals having states indicative of stabilized and non-stabilized states of operations of corresponding portions of said internal circuitry by providing, in accordance with a plurality of shorter time delays, a plurality of corresponding delayed ready signals;

longer delay circuitry responsive to said plurality of ready signals and a plurality of enable signals having states indicative of enabled and non-enabled states of operations of said corresponding portions of said internal circuitry by providing a plurality of corresponding logic signals indicative of said states of respective pairs of one of said plurality of enable signals and one of said plurality of ready signals, and, in accordance with a plurality of longer time delays, a plurality of corresponding delayed logic signals and a plurality of corresponding inverse delayed logic signals; and

encoding circuitry coupled to said shorter delay circuitry and said longer delay circuitry, and responsive to said plurality of enable signals, said plurality of ready signals, said plurality of logic signals, said plurality of delayed logic signals, and said plurality of inverse delayed logic signals by providing a status signal having time multiplexed states which are indicative of a power on reset condition for external circuitry following one or more of said enabled states of operations of said corresponding portions of said internal circuitry, and are further indicative of one or more of said stabilized states of operations of said corresponding portions of said internal circuitry, wherein

said status signal is in a de-asserted state when each of said plurality of enable signal states is indicative of said non-enabled states of operations of corresponding portions of said internal circuitry,

said status signal transitions to and remains in an asserted state, during at least an interval substantially equal to one of said plurality of longer time delays, in response to a first one of said plurality of enable signal states becoming indicative of said enabled state of operation of a first corresponding portion of said internal circuitry, following which, in response to a first one of said plurality of ready signal states being indicative of said stabilized state of operation of said first corresponding portion of said internal circuitry, said status signal transitions to said de-asserted state,

during said enabled and stabilized states of operation of said first corresponding portion of said internal circuitry and following a second one of said plurality of enable signal states becoming indicative of said enabled state of operation of a second corresponding portion of said internal circuitry, said status signal remains in said de-asserted state during at least an interval substantially equal to one of said plurality of shorter time delays, following which,

in response to a second one of said plurality of ready signal states being indicative of said stabilized state of operation of said second corresponding portion of said internal circuitry, said status signal remains in said de-asserted state, and

in response to said second one of said plurality of ready signal states being indicative of said non-stabilized state of operation of said second corresponding portion of said internal circuitry, said status signal transitions to said asserted state, and

said status signal transitions to and remains in said asserted state in response to said first and second ones of said plurality of enable signal states concurrently becoming indicative of said enabled states of operations of said first and second corresponding portions of said internal circuitry, following which and after said first one of said plurality of ready signal states becomes and remains indicative of said stabilized state of operation of said first corresponding portion of said internal circuitry during at least an interval substantially equal to one of said plurality of longer time delays, said status signal transitions to said de-asserted state, further following which, in response to one of said first and second ready signal states becoming indicative of said non-stabilized state of operation of one of said first and second corresponding portions of said internal circuitry, said status signal transitions to said asserted state.

2. The apparatus of claim 1, wherein said shorter delay circuitry comprises a plurality of monostable multivibrator circuits responsive to said plurality of ready signals by providing said plurality of corresponding delayed ready signals.

3. The apparatus of claim 1, wherein said longer delay circuitry comprises logic circuitry responsive to said respective pairs of one of said plurality of enable signals and one of said plurality of ready signals by providing said plurality of corresponding logic signals.

4. The apparatus of claim 1, wherein said longer delay circuitry comprises a plurality of monostable multivibrator circuits responsive to said plurality of corresponding logic signals by providing said plurality of corresponding delayed logic signals and said plurality of corresponding inverse delayed logic signals.

5. The apparatus of claim 1, wherein said encoding circuitry comprises a plurality of combinational logic circuits.

6. An apparatus including an integrated circuit having internal circuitry for providing, via a single output electrode, a status signal having time multiplexed states indicative of a power on reset condition for external circuitry following enablement of operations of portions of said internal circuitry, and further indicative of subsequent operation statuses of said internal circuitry portions, comprising:

a plurality of enablement electrodes to convey a plurality of enable signals having states indicative of enabled and non-enabled states of operations of corresponding portions of said internal circuitry;

a plurality of readiness electrodes to convey a plurality of ready signals having states indicative of stabilized and non-stabilized states of operations of said corresponding portions of said internal circuitry;

an output electrode to convey a status signal having time multiplexed states which are indicative of a power on reset condition for external circuitry following one or more of said enabled states of operations of said corresponding portions of said internal circuitry, and are further indicative of one or more of said stabilized states of operations of said corresponding portions of said internal circuitry;

shorter delay circuitry coupled to said plurality of readiness electrodes and responsive to said plurality of ready signals by providing, in accordance with a plurality of shorter time delays, a plurality of corresponding delayed ready signals;

longer delay circuitry coupled to said plurality of enablement electrodes and said plurality of readiness electrodes, and responsive to said plurality of enable signals and said plurality of ready signals by providing a corresponding plurality of logic signals indicative of said states of respective pairs of one of said plurality of enable signals and one of said plurality of ready signals, and, in accordance with a plurality of longer time delays, a plurality of corresponding delayed logic signals and a plurality of corresponding inverse delayed logic signals; and

encoding circuitry coupled to said plurality of enablement electrodes, said plurality of readiness electrodes, said shorter delay circuitry, said longer delay circuitry, and said output electrode, and responsive to said plurality of enable signals, said plurality of ready signals, said plurality of logic signals, said plurality of delayed logic signals, and said plurality of inverse delayed logic signals by providing said status signal, wherein

said status signal is in a de-asserted state when each of said plurality of enable signal states is indicative of said non-enabled states of operations of corresponding portions of said internal circuitry,

when one of said plurality of enable signal states becomes indicative of said enabled state of operation of a corresponding portion of said internal circuitry, said status signal transitions to and remains in an asserted state during at least an interval substantially equal to one of said plurality of longer time delays, and, if a corresponding one of said plurality of ready signal states has also become and remained indicative of said stabilized state of operation of said corresponding portion of said internal circuitry during at least another interval substantially equal to another of said plurality of longer time delays, said status signal transitions to a de-asserted state, following which said status signal state follows said corresponding one of said plurality of ready signal states,

when, after one of said plurality of enable signal states is indicative of said enabled state of operation of a corresponding portion of said internal circuitry and a corresponding one of said plurality of ready signal states has become indicative of said stabilized state of operation of said corresponding portion of said internal circuitry, another of said plurality of enable signal states becomes indicative of said enabled state of operation of another corresponding portion of said internal circuitry, said status signal remains in said de-asserted state during at least an interval substantially equal to one of said plurality of shorter time delays, following which said status signal remains in said de-asserted state so long as each one of said plurality of ready signal states remains indicative of said stabilized states of operation of said corresponding portions of said internal circuitry, and transitions to said asserted state otherwise, and

when, substantially concurrently, each one of said plurality of enable signal states becomes indicative of said enabled states of operation of said corresponding portions of said internal circuitry, said status signal transitions to and remains in said asserted state during at least an interval substantially equal to one of said plurality of longer time delays, following which said status signal transitions to said de-asserted state, further following which said status signal transitions to said asserted state in response to one of said plurality of ready signal states becoming indicative of said non-stabilized state of operation of said corresponding portion of said internal circuitry.

7. The apparatus of claim 6, wherein said shorter delay circuitry comprises a plurality of monostable multivibrator circuits responsive to said plurality of ready signals by providing said plurality of corresponding delayed ready signals.

8. The apparatus of claim 6, wherein said longer delay circuitry comprises logic circuitry responsive to said respective pairs of one of said plurality of enable signals and one of said plurality of ready signals by providing said plurality of corresponding logic signals.

9. The apparatus of claim 6, wherein said longer delay circuitry comprises a plurality of monostable multivibrator circuits responsive to said plurality of corresponding logic signals by providing said plurality of corresponding delayed logic signals and said plurality of corresponding inverse delayed logic signals.

10. The apparatus of claim 6, wherein said encoding circuitry comprises a plurality of combinational logic circuits.

11. A method for providing, via a single output electrode of an integrated circuit having internal circuitry, a status signal having time multiplexed states indicative of a power on reset condition for external circuitry following enablement of operations of portions of said internal circuitry, and further indicative of subsequent operation statuses of said internal circuitry portions, comprising:

receiving a plurality of ready signals having states indicative of stabilized and non-stabilized states of operations of corresponding portions of said internal circuitry, and in response thereto providing, in accordance with a plurality of shorter time delays, a plurality of corresponding delayed ready signals;

receiving said plurality of ready signals and a plurality of enable signals having states indicative of enabled and non-enabled states of operations of said corresponding portions of said internal circuitry, and in response thereto providing a plurality of corresponding logic signals indicative of said states of respective pairs of one of said plurality of enable signals and one of said plurality of ready signals, and, in accordance with a plurality of longer time delays, a plurality of corresponding delayed logic signals and a plurality of corresponding inverse delayed logic signals; and

receiving said plurality of enable signals, said plurality of ready signals, said plurality of logic signals, said plurality of delayed logic signals, and said plurality of inverse delayed logic signals, and in response thereto providing a status signal having time multiplexed states which are indicative of a power on reset condition for external circuitry following one or more of said enabled states of operations of said corresponding portions of said internal circuitry, and are further indicative of one or more of said stabilized states of operations of said corresponding portions of said internal circuitry, wherein

said status signal is in a de-asserted state when each of said plurality of enable signal states is indicative of said non-enabled states of operations of corresponding portions of said internal circuitry,

said status signal transitions to and remains in an asserted state, during at least an interval substantially equal to one of said plurality of longer time delays, in response to a first one of said plurality of enable signal states becoming indicative of said enabled state of operation of a first corresponding portion of said internal circuitry, following which, in response to a first one of said plurality of ready signal states being indicative of said stabilized state of operation of said first corresponding portion of said internal circuitry, said status signal transitions to said de-asserted state,

during said enabled and stabilized states of operation of said first corresponding portion of said internal circuitry and following a second one of said plurality of enable signal states becoming indicative of said enabled state of operation of a second corresponding portion of said internal circuitry, said status signal remains in said de-asserted state during at least an interval substantially equal to one of said plurality of shorter time delays, following which,

in response to a second one of said plurality of ready signal states being indicative of said stabilized state of operation of said second corresponding portion of said internal circuitry, said status signal remains in said de-asserted state, and

in response to said second one of said plurality of ready signal states being indicative of said non-stabilized state of operation of said second corresponding portion of said internal circuitry, said status signal transitions to said asserted state, and

said status signal transitions to and remains in said asserted state in response to said first and second ones of said plurality of enable signal states concurrently becoming indicative of said enabled states of operations of said first and second corresponding portions of said internal circuitry, following which and after said first one of said plurality of ready signal states becomes and remains indicative of said stabilized state of operation of said first corresponding portion of said internal circuitry during at least an interval substantially equal to one of said plurality of longer time delays, said status signal transitions to said de-asserted state, further following which, in response to one of said first and second ready signal states becoming indicative of said non-stabilized state of operation of one of said first and second corresponding portions of said internal circuitry, said status signal transitions to said asserted state.

12. The method of claim 11, wherein said receiving a plurality of ready signals having states indicative of stabilized and non-stabilized states of operations of corresponding portions of said internal circuitry, and in response thereto providing, in accordance with a plurality of shorter time delays, a plurality of corresponding delayed ready signals comprises triggering a plurality of monostable multivibrator circuits with said plurality of ready signals to provide said plurality of corresponding delayed ready signals.

13. The method of claim 11, wherein said receiving said plurality of ready signals and a plurality of enable signals having states indicative of enabled and non-enabled states of operations of said corresponding portions of said internal circuitry, and in response thereto providing a plurality of corresponding logic signals indicative of said states of respective pairs of one of said plurality of enable signals and one of said plurality of ready signals, and, in accordance with a plurality of longer time delays, a plurality of corresponding delayed logic signals and a plurality of corresponding inverse delayed logic signals comprises logically processing said respective pairs of one of said plurality of enable signals and one of said plurality of ready signals to provide said plurality of corresponding logic signals.

14. The method of claim 11, wherein said receiving said plurality of ready signals and a plurality of enable signals having states indicative of enabled and non-enabled states of operations of said corresponding portions of said internal circuitry, and in response thereto providing a plurality of corresponding logic signals indicative of said states of respective pairs of one of said plurality of enable signals and one of said plurality of ready signals, and, in accordance with a plurality of longer time delays, a plurality of corresponding delayed logic signals and a plurality of corresponding inverse delayed logic signals comprises triggering a plurality of monostable multivibrator circuits with said plurality of corresponding logic signals to provide said plurality of corresponding delayed logic signals and said plurality of corresponding inverse delayed logic signals.

15. The method of claim 11, wherein said receiving said plurality of enable signals, said plurality of ready signals, said plurality of logic signals, said plurality of delayed logic signals, and said plurality of inverse delayed logic signals, and in response thereto providing a status signal having time multiplexed states which are indicative of a power on reset condition for external circuitry following one or more of said enabled states of operations of said corresponding portions of said internal circuitry, and are further indicative of one or more of said stabilized states of operations of said corresponding portions of said internal circuitry comprises logically processing selected combinations of said plurality of enable signals, said plurality of ready signals, said plurality of logic signals, said plurality of delayed logic signals, and said plurality of inverse delayed logic signals.