Extended dynamic range watchdog timer
AssigneeTexas Instruments Incorporated
InventorsKatsunobu Hirakawa, Weifeng Joe Zhou, Jay B. Reimer
Life of this patent
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Abstract
A data processor timer comprising a writeable control register, a look-up table and a loadable counter. The loadable counter operates in a first mode to load the count data field and operates in a second mode an entry from said look-up table specified by the count data field. The loadable counter generating a time out signal upon counting a number of clock pulses equal to said count. The writeable control register preferably includes a mode bit selecting the first or second modes. This invention is suitable for a pre-scalar counter as part of a data processor watchdog timer.
Claims10
A data processor timer comprising:
- a writeable control register including a count data field having of N bits;
- a look-up table having an input of N bits connected to said count data field of said writeable control register and 2N data entries, each data entry having M bits where M is greater than N, each N bit input specifying one said 2N entries for output;
- and
- a loadable counter storing a count, receiving and counting clock pulses, said loadable counter operable in a first mode to load as said count said count data field and operable in a second mode to load said count an entry from said look-up table specified by said count data field, said loadable counter generating a time out signal upon counting a number of clock pulses equal to said count.
A data processor watchdog timer comprising:
- a writeable control register including a pre-scalar count data field having of N bits;
- a look-up table having an input of N bits connected to said pre-scalar count data field of said writeable control register and 2N data entries, each data entry having M bits where M is greater than N, each N bit input specifying one said 2N entries for output;
- and
- a first loadable counter storing a first count, receiving and counting clock pulses, said loadable counter operable in a first mode to load as said first count said pre-scalar count data field and operable in a second mode to load as said first count an entry from said look-up table specified by said pre-scalar count data field, said loadable counter generating a pre-scalar count signal upon counting a number of clock pulses equal to said count;
- a time period register storing a second count;
- a second loadable counter storing a second count, receiving and counting pre-scalar count signals from said first loadable counter, said second loadable counter operable to load as said second count said second stored in said time period register, said second loadable counter generating an interrupt to said data processor upon counting a number of pre-scalar count signals equal to said second count.
Dependencies are inferred from the claim text.