摘要:
A memory controller controls the operation of a number of memory module units and includes a number of queues which couple to the module units. Each queue includes an address queue register, a control queue register and a data queue register. Each address queue register has tristate control for independent operation. Control circuits which couple to the queue address, control and data registers assign memory cycles between queues on an alternate basis when the queue control registers store requests which are being processed. This enables the interleaving of memory requests which eliminates processing delays particularly in cases where such requests involve multiword transfers over successive memory cycles of operation.
摘要:
A memory subsystem which couples to a multiword bus for processing memory requests received therefrom includes at least a pair of independently addressable dynamic memory module units. Each memory unit includes a number of rows of random access memory (RAM) chips. The subsystem further includes an adder circuit, a pair of tri-state operated address register circuits and timing circuits. The address circuits include a pair of tri-state operated address registers which couple to the bus and to the set of address lines to each memory unit. In response to a memory request, the registers store row and column address portions of a chip address of the memory request. A multibit adder circuit is connected to increment by one the low order row address when the least significant address bits of the memory request indicate a subboundary address condition thereby enabling access to a pair of sequential word locations. Whenever a memory request specifies an address which cannot access a double word, boundary circuits upon detecting the condition cause the timing circuits to generate only timing signals necessary for accessing the first word location.
摘要:
A memory system includes at least one or more memory module boards identical in construction and a single computer board containing the control circuits for controlling memory operations. Each board plugs into the main board and includes a memory section having a number of rows of memory chips and an identification section containing circuits for generating signals indicating the board density and the type of memory parts used in constructing the board's memory section. The main board control circuits include a number of decoder circuits which couple to the identification and to the memory section of each memory module board. The decoder circuits receive different address bit combinations of a predetermined multibit address portion of each memory request address. In response to signals generated by the identification sections of the installed memory boards, the decoder circuits are selectively enabled to decode those bit combinations of the address portion specified by the sections for enabling successive addressing of all of the blocks of location within the system.
摘要:
Soft error rewrite control apparatus is included within a memory system for rendering the semiconductor memory modules less susceptible to single bit errors produced by alpha particles and other system disturbances. During a number of successive memory cycles occurring at a predetermined rate, the soft error rewrite control apparatus enables the read out of information stored within each module location, the correction of any single bit errors contained therein and the rewriting of the corrected information back into such location. Diagnostic apparatus is further included which is connected to place the memory system in a state for testing and verifying the operation of the soft error control apparatus. Also, the diagnostic apparatus is connected to condition the soft error control apparatus for operating in a high speed mode enabling the read out correction and rewriting of each location to take place within a minimum amount of time. By monitoring the status of the information being corrected, the diagnostic apparatus is able to signal whether or not the soft error control apparatus is operating properly.
摘要:
A printed circuit board assembly includes at least two layers which is able to accommodate a subsystem such as a memory subsystem designed to have one or more optional features. The two layers of the printed circuit board when etched include the required number of horizontal and vertical paths to be connected to all of the integrated circuit chips to be positioned and interconnected thereon. The required holes for such integrated circuit chips when drilled include first sets of holes for mounting groups of integrated circuit chips required for implementing a first group of features and which are to be interconnected to the other integrated circuit chips of the subsystem mounted on the different sections of the board. Second sets of holes are included on the board so as to have a predetermined relationship with the first sets of holes for mounting alternative groups of integrated circuit chips to be interconnected in a manner to implement other features. Thereafter, the circuit board is populated with only those integrated circuit chips required for construction of a memory subsystem with one or more selected features.
摘要:
Apparatus and a method for generating timing signals to be utilized in latched type memories only when the address signals are valid. A CAS signal is generated in response to an RAS signal via a device which tracks the worst case delay of memory address signals and does not permit the application of the CAS signal to memory until the worst case delay of the memory address signals has been accounted for.A memory array is comprised of any combination of latched or non-latched tri-state memories. The latched memories are coupled to a data bus utilizing conventional TTL circuits in combination with a power driver to simulate conventional tri-state buffer circuits. When the power driver/drivers remove(s) power from TTL circuits, the tri-state characteristics are simulated; whereas when the power driver applies power to the TTL circuits, they operate in their normal mode and present a normal impedance between the data bus and data-out lines of the memory array.
摘要:
Apparatus is included in a main memory subsystem of a data processing system which receives multibyte data from a plurality of input/output devices connected to a common bus. During a write cycle of operation, a device applies the multibyte data signals together with associated parity bits for writing into an addressed storage location of memory. During the write cycle, error encoder circuits generate check code bits from the multibyte data and parity bits which are coded to signal selectively the presence of a multibyte uncorrectable error condition in accordance with the parity bits from a device. During a read cycle of operation, error detection and correction decoder circuits connected to the memory in response to the data and check bits read out from an addressed location are operative to generate a number of syndrome bits. These bits have a predetermined characteristic for indicating the existence of an uncorrectable error condition when one or more data bytes were in error and there was a single bit error in memory.
摘要:
Refresh and initialize counter circuits included within a dynamic memory system are supplemented with additional counter control circuits for synchronizing them from the same timing source which drives the refresh and initialize counter circuits. The counter control circuits count in accordance with modulus one less than a maximum count so as to generate a sequence of counts over a corresponding number of cycles of operation for selection of row and column addresses which enable the information stored in each location of the memory system to be read out, corrected for single bit errors and rewritten back thereby rendering the system less susceptible to soft errors such as those produced by alpha particles.
摘要:
A memory controller couples to a bus and controls a number of memory module units or memory modules. The controller includes a number of queue circuits for processing a variety of different types of memory requests received from a number of command generating units coupled to the bus requiring the controller to operate in a corresponding number of different modes. The controller includes queue timing and control apparatus which couples to the modules and to the queue circuits for minimizing conflicts between the types of requests and the internal operations required to be performed by the controller.
摘要:
A printed circuit board assembly includes at least two layers which is able to accommodate a subsystem such as a memory subsystem designed to have one or more optional features. The two layers of the printed circuit board when etched include the required number of horizontal and vertical paths to be connected to all of the integrated circuit chips to be positioned and interconnected thereon. The required holes for such integrated circuit chips when drilled include first sets of holes for mounting groups of integrated circuit chips required for implementing a first group of features and which are to be interconnected to the other integrated circuit chips of the subsystem mounted on the different sections of the board. Second sets of holes are included on the board so as to have a predetermined relationship with the first sets of holes for mounting alternative groups of integrated circuit chips to be interconnected in a manner to implement other features. Thereafter, the circuit board is populated with only those integrated circuit chips required for construction of a memory subsystem with one or more selected features.