摘要:
A dual bus microcomputer system including a cache subsystem improves performance under certain circumstances by allowing programmable control over the LOCK function. More particularly, additional logic is coupled between the LOCK output of the CPU and the LOCK input of the cache controller. A control bit from an I/O port is a second input to the additional logic. With the control bit in one state, the logic allows the LOCK input to follow the LOCK output. In the other state of the control bit, the LOCK input is disabled regardless of the state of the LOCK output.
摘要:
A microprocessor system employing an 80386 CPU and an 82385 cache controller has the capability of functioning with dynamic bus sizing (where the CPU interacts with devices which may or may not be 32-bits wide), as well as posted write capability. Unfortunately, the two capabilities have the possibility of an incompatibility if a write cycle is posted to a device which cannot transfer 32 bits on a single cycle. The present invention provides logic to overcome this incompatibility. An address decoder is provided to decode the tag portion of an address asserted on a CPU bus to determine if the asserted address is inside or outside a range of addresses which define cacheable devices. Any cacheable device is by definition 32 bits wide and therefore posted writes are allowed only to cacheable devices. Accordingly, the microcomputer system employing the invention posts write cycles to cacheable devices; write cycles to non-cacheable devices are inhibited from being posted.
摘要:
A logic circit external to a microprocessor monitors selected processor I/O pins to determine the current processor cycle and, in response to a hold request signal, drives the processor into a hold state at the appropriate time in the cycle. The logic circuit also includes a "lockbus" feature that, when the processor is not idle, "locks" the microprocessor to the local CPU bus for a predetermined period of time immediately after the processor is released from a hold state.
摘要:
The capacity of cache memory supported by a cache controller can be increased by offsetting the relationship between CPU address output terminals and address input terminals of the cache controller and correspondingly doubling the cache line size. In some cases, additional logic generates a hidden memory cycle so as to fetch from memory that number of bytes equal to the new line size regardless of the width of the data bus. The hidden memory cycle is initiated by a read miss and further logic generates a memory address which is not generated by the CPU. The hidden memory cycle is maintained transparent to the CPU and cache controller by inhibiting the change in a READY signal until completion of both the normal memory cycle and the hidden memory cycle.
摘要:
A microcomputer system employing an 80386 CPU and an 82385 cache controller has the capability of functioning with dynamic bus sizing (where the CPU interacts with devices which may or may not be 32-bits wide), as well as posted write capability. Unfortunately, the two capabilities have the possibility of an incompatibility if a write cycle is posted to a device which cannot transfer 32 bits on a single cycle. The present invention provides logic to overcome this incompatibility. An address decoder is provided to decode the tag portion of an address asserted on a CPU local bus to determine if the asserted address is inside or outside a range of addresses which define cacheable devices. Any cacheable device is by definition 32 bits wide and therefore posted writes are allowed only to cacheable devices. Accordingly, the microcomputer system employing the invention posts write cycles to cacheable devices; write cycles to non-cacheable devices are inhibited from being posted.
摘要:
In an 80386/82385 microcomputer system, the timing requirements placed on non-cache memory components by the 82385 are more stringent than the timing requirements placed on the non-cache memory components by the 80386. The present invention operates on the 82385 cache write enable (CWE) signals, and delays those signals in the event of a read miss. Delaying the CWE signals relaxes the timing requirements placed on non-cache memory components and at the same time does not impact wait state parameters for read miss operations.
摘要:
Any incompatibility between pipelined operations (such as is available in the 80386) and dynamic bus sizing (allowing the processor to operate with devices of 8-, 16- and 32-bit sizes) is accommodated by use of an address decoder and ensuring that device addresses for cacheable devices are in a first predetermined range and any device addresses for non-cacheable devices are not in that predetermined range. Since by definition cacheable devices are 32-bit devices, pipelined operation is allowed only if the address decoder indicates the access is to a cacheable device. In that event, a next address signal is provided to the 80386. This allows the 80386 to proceed to a following cycle prior to completion of the previous cycle. For accesses which are to devices whose address indicate they are non-cacheable, a next address signal is withheld until the cycle is completed, i.e. without pipelining. The invention further provides for proper interface between a DMA mechanism (driven by a first clock) and a CPU local bus subsystem (driven by an entirely different clock). Data provided by the DMA mechanism is latched into an interface between the CPU local bus and the system bus, and a DMA cycle completed. Only after completion of the DMA cycle is detected, is the cycle on the CPU local bus allowed to complete. In this fashion, the CPU can go on to a following operation and be assured that the DMA mechanism is no longer driving the system bus.
摘要:
Methods, apparatuses, and computer program products for dynamically reconfiguring a primary processor identity within a multi-processor socket server are provided. Embodiments include detecting, by the service processor, a processor socket reconfiguration event corresponding to a first processor socket; disabling, by the service processor, the first processor socket of the server in response to detecting the processor socket reconfiguration event; and reassigning, by the service processor, the primary processor identity to a second processor socket of the server.
摘要:
Methods, apparatuses, and computer program products for dynamically reconfiguring a primary processor identity within a multi-processor socket server are provided. Embodiments include detecting, by the service processor, a processor socket reconfiguration event corresponding to a first processor socket; disabling, by the service processor, the first processor socket of the server in response to detecting the processor socket reconfiguration event; and reassigning, by the service processor, the primary processor identity to a second processor socket of the server.
摘要:
A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design is for securing of leased resources on a computer. The design structure includes a computer for securing resources may comprise at least one processor, a plurality of resources, wherein each resource is associated with configuration data and a programmable logic device connected to each of the plurality of resources. The programmable logic device may be configured for determining whether a resource is leased, reading un-encoded configuration data from a resource, and sending the configuration data to a first unit, if the resource is not leased. The programmable logic device may further be configured for reading encoded configuration data from a resource, decoding the configuration data, sending the configuration data that was decoded to a first unit, and logging use of the resource by the first unit, if the resource is leased.