Abstract: Redundant time-of-day (TOD) oscillators are aligned, within a master oscillator path, to local logic oscillator and used to create independent step-sync signals. A step checker validates and provides selection signals to identify which of the TOD oscillators operates according to a criterion. Independent step-sync signals are transmitted to several sibling chips. Local step and sync signals are delayed to arrive at TOD register nearly synchronous with TOD registers in sibling chips. A slave oscillator path may be used to select time signals generated in a sibling chip, whereby the master oscillator path is deselected. A primary control register set may be used to configure which among several chips is a master chip using the master oscillator path. All remaining chips are slave chips. All segments of the topology are redundant. One of multiple possible alternate topologies is defined in a secondary control register set.

Abstract: A method for automatic scan completion in the event of a system checkstop in a processor. The processor includes: a processor register; a millicode interface connected between the processor register and a checkstop scan controller; a checkstop logic circuit connected between the checkstop scan controller and a checkstop scan engine; and a scan chain engine and a scan chain connected to the checkstop scan engine. The method includes (a) upon occurrence of a checkstop serially reading data from a processor register and serially writing the data to latches of a scan chain register; and (b) upon occurrence of a system checkstop during (a), stopping the reading and writing and moving data sent before the system checkstop from latches of the scan chain where the data was stored when the system checkstop occurred to latches where the data would have been stored if the system checkstop had not occurred.

Abstract: A digital system and method of operating the same. The system comprises a processor chip including a first elastic interface domain, wherein the first elastic interface domain comprises a first processor X logic and a first processor Y logic, wherein the first processor X and Y logic comprise first X and Y latches, respectively; and a first ASIC chip electrically coupled to the processor chip, wherein the first processor X and Y logics are configured to be simultaneously in a functional mode, wherein the first processor X logic is configured to switch from the functional mode to a scanning mode while the first processor Y logic remains in the functional mode, and wherein in response to the first processor Y logic being in the functional mode, the first processor Y logic is configured to generate a first reference ASIC clock signal to the first ASIC chip.

Abstract: A computer implemented method and data processing system are provided for preventing firmware defects from disrupting logic clocks. In response to a firmware interface requesting a scan operation for a functional unit, protection logic allows a scan enable to activate to the functional unit only if the logic clocks are stopped to that functional unit, otherwise the scan enable is not activated, an error is indicated, and an interrupt is presented to firmware. Also, in response to a command from a firmware interface to stop the logic clocks to a functional unit, protection logic allows the clocks to be stopped to the functional unit only if the functional unit is already indicating a catastrophic error, otherwise the clocks are not stopped, an error is indicated, and an interrupt is presented to firmware.

Abstract: The various embodiments described herein relate to a system for performing a serial communication between a central control block and a plurality of satellite components within a semiconductor chip. The system comprises at least one logical ring that serially connects the satellite components to the central control block. The system further comprises a centralized timer. The satellite components aid the system in obeying protocols and performing direct accesses to and/or from registers. The logical ring comprises at least one data channel that is provided for transmitting data packets and address packets. Single-envelope transactions are implemented. Errors of the satellite components associated with the single-envelope transactions are reported to the central control block as additional acknowledgement information.

Abstract: A new multi nodal computer system comprising a number of nodes on which chips of different types reside. The new multi nodal computer system is characterized in that there is one clock chip per node, each clock chip controlling only the chips residing on that node said chips being appropriate for sending a check stop request to the associated clock chip in case of a malfunction. A new check stop handling method is characterized in that depending on the source of the check stop request the clock chip that received the check stop request initiates a system check stop, a node check up, or a chip check stop.

Abstract: Redundant time-of-day (TOD) oscillators are aligned, within a master oscillator path, to local logic oscillator and used to create independent step-sync signals. A step checker validates and provides selection signals to identify which of the TOD oscillators operates according to a criterion. Independent step-sync signals are transmitted to several sibling chips. Local step and sync signals are delayed to arrive at TOD register nearly synchronous with TOD registers in sibling chips. A slave oscillator path may be used to select time signals generated in a sibling chip, whereby the master oscillator path is deselected. A primary control register set may be used to configure which among several chips is a master chip using the master oscillator path. All remaining chips are slave chips. All segments of the topology are redundant. One of multiple possible alternate topologies is defined in a secondary control register set.

Abstract: The present invention provides a new multi nodal computer system comprising a number of nodes on which chips of different types reside. The new multi nodal computer system is characterized in that there is one clock chip per node, each clock chip controlling only the chips residing on that node said chips being appropriate for sending a check stop request to the associated clock chip in case of a malfunction. A new check stop handling method is characterized in that depending on the source of the check stop request the clock chip that received the check stop request initiates a system check stop, a node check up, or a chip check stop.

Abstract: Redundant time-of-day (TOD) oscillators are aligned, within a master oscillator path, to local logic oscillator and used to create independent step-sync signals. A step checker validates and provides selection signals to identify which of the TOD oscillators operates according to a criterion. Independent step-sync signals are transmitted to several sibling chips. Local step and sync signals are delayed to arrive at TOD register nearly synchronous with TOD registers in sibling chips. A slave oscillator path may be used to select time signals generated in a sibling chip, whereby the master oscillator path is deselected. A primary control register set may be used to configure which among several chips is a master chip using the master oscillator path. All remaining chips are slave chips. All segments of the topology are redundant. One of multiple possible alternate topologies is defined in a secondary control register set.

Abstract: Redundant time-of-day (TOD) oscillators are aligned, within a master oscillator path, to local logic oscillator and used to create independent step-sync signals. A step checker validates and provides selection signals to identify which of the TOD oscillators operates according to a criterion. Independent step-sync signals are transmitted to several sibling chips. Local step and sync signals are delayed to arrive at TOD register nearly synchronous with TOD registers in sibling chips. A slave oscillator path may be used to select time signals generated in a sibling chip, whereby the master oscillator path is deselected. A primary control register set may be used to configure which among several chips is a master chip using the master oscillator path. All remaining chips are slave chips. All segments of the topology are redundant. One of multiple possible alternate topologies is defined in a secondary control register set.

Abstract: Techniques for accounting microprocessor resource consumption. The present invention provides an automatic method to timely determine the current microprocessor clock frequency. Information provided by timer facilities of the microprocessor is reused by sampling this information at constant intervals. Such direct derivation of the microprocessor clock frequency is a real-time method that also takes into consideration secondary effects. Examples for such secondary effects include clock frequency variations across chips due to manufacturing variations, any degradation due to performance loss by thermal, or other detrimental effects as well as any voltage changes. In the preferred embodiment of the invention, the real-time microprocessor clock frequency determination is implemented as part of the microprocessor itself. No additional service processors or other external hardware facilities are needed in order to control the microprocessor clock frequency determination function.

Abstract: A computer implemented method and data processing system are provided for preventing firmware defects from disrupting logic clocks. In response to a firmware interface requesting a scan operation for a functional unit, protection logic allows a scan enable to activate to the functional unit only if the logic clocks are stopped to that functional unit, otherwise the scan enable is not activated, an error is indicated, and an interrupt is presented to firmware. Also, in response to a command from a firmware interface to stop the logic clocks to a functional unit, protection logic allows the clocks to be stopped to the functional unit only if the functional unit is already indicating a catastrophic error, otherwise the clocks are not stopped, an error is indicated, and an interrupt is presented to firmware.

Abstract: The present invention relates to system clocking in computer systems. In particular, it relates to system clocking in high-end multi-processor, multi-node server computer systems with an enhanced degree of performance and reliability and to a method for dynamically switching between a first and a second clock signal, if the first should fail. More redundancy even to the Dynamic Clock Switching Circuit (DCSC) (14) and the wiring (17) from there to multiple, PLL-(12) free clock chips (22) is provided. Instead of only one DCSC (14) and one single wiring (17), two of them (14-0, 14-1; 17-0, 17-1) are used combined with a further particular logic present on each clock chip (22), which in combination generate two synchronous, fine-tuned, minimum-shifted clock signals and select always the first of them to arrive at a FlipFlop controlling the output for clock distribution wiring.

Abstract: The present invention relates to system clocking in computer systems. In particular, it relates to system clocking in high-end multi-processor, multi-node server computer systems with an enhanced degree of performance and reliability and to a method for dynamically switching between a first and a second clock signal, if the first should fail. More redundancy even to the Dynamic Clock Switching Circuit (DCSC) (14) and the wiring (17) from there to multiple, PLL-(12) free clock chips (22) is provided. Instead of only one DCSC (14) and one single wiring (17), two of them (14-0, 14-1; 17-0, 17-1) are used combined with a further particular logic present on each clock chip (22), which in combination generate two synchronous, fine-tuned, minimum-shifted clock signals and select always the first of them to arrive at a FlipFlop controlling the output for clock distribution wiring.

Abstract: Redundant time-of-day (TOD) oscillators are aligned, within a master oscillator path, to local logic oscillator and used to create independent step-sync signals. A step checker validates and provides selection signals to identify which of the TOD oscillators operates according to a criterion. Independent step-sync signals are transmitted to several sibling chips. Local step and sync signals are delayed to arrive at TOD register nearly synchronous with TOD registers in sibling chips. A slave oscillator path may be used to select time signals generated in a sibling chip, whereby the master oscillator path is deselected. A primary control register set may be used to configure which among several chips is a master chip using the master oscillator path. All remaining chips are slave chips. All segments of the topology are redundant. One of multiple possible alternate topologies is defined in a secondary control register set.

Abstract: The present invention provides a new multi nodal computer system comprising a number of nodes on which chips of different types reside. The new multi nodal computer system is characterized in that there is one clock chip per node, each clock chip controlling only the chips residing on that node said chips being appropriate for sending a check stop request to the associated clock chip in case of a malfunction. A new check stop handling method is characterized in that depending on the source of the check stop request the clock chip that received the check stop request initiates a system check stop, a node check up, or a chip check stop.