Synchronous memory device having identification register
First Claim
1. A synchronous memory device having a memory cell array divided into a plurality of subarrays, wherein each subarray includes a plurality of subarray sections and each subarray section includes a plurality of memory cells, the memory device comprising:
- clock receiver circuitry to receive at least a first external clock signal from an external bus;
clock generation circuitry, coupled to the clock receiver circuitry, to generate a first internal clock signal having a clock edge which is synchronized with the first external clock signal and to generate a second internal clock signal having a clock edge which is synchronized with the first external clock signal;
a programmable register to store first identification information wherein the first identification information identifies the memory device;
interface circuitry coupled to the external bus to receive a read request and second identification information;
a first subarray section having a first internal I/O line to access data from a first memory cell location and a second internal I/O line to access data from a second memory cell location, wherein the first and second memory cell locations are in the first subarray section;
a second subarray section having a first internal I/O line to access data from a third memory cell location and a second internal I/O line to access data from a fourth memory cell location, wherein the third and fourth memory cell locations are in the second subarray section;
output driver circuitry, including a first output driver and a second output driver, to output data onto the external bus in response to the read request when the first identification information corresponds to the second identification information; and
multiplexer circuitry, coupled to the output driver circuitry, wherein;
the multiplexer circuitry couples the first internal I/O line of the first subarray section to an input of the first output driver and couples the first internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the first internal clock signal; and
the multiplexer circuitry couples the second internal I/O line of the first subarray section to an input of the first output driver and couples the second internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the second internal clock signal.
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Accused Products
Abstract
The present invention is directed to a synchronous memory device having a memory cell array divided into a plurality of subarrays, including first and second subarrays each having a plurality of subarray sections. The memory device further includes a device identification register to store an identification code to identify the memory device. A first subarray section in the memory device includes a first internal I/O line to access data from a first memory cell location in the first subarray section and a second internal I/O line to access data from a second memory cell location in the first subarray section. A second subarray section in the memory device includes a first internal I/O line to access data from a third memory cell location in the second subarray section and a second internal I/O line to access data from a fourth memory cell location in the second subarray section. In addition, the memory device includes output driver circuitry, including a first output driver and a second output driver, to output data onto the external bus in response to the read request when the identification information corresponds to the identification code. Multiplexer circuitry couples the first internal I/O line of the first subarray section to an input of the first output driver and couples the first internal I/O line of the second subarray section to an input of the second output driver in response to a clock edge of a first internal clock signal; and couples the second internal I/O line of the first subarray section to an input of the first output driver and couples the second internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the second internal clock signal.
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Citations
37 Claims
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1. A synchronous memory device having a memory cell array divided into a plurality of subarrays, wherein each subarray includes a plurality of subarray sections and each subarray section includes a plurality of memory cells, the memory device comprising:
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clock receiver circuitry to receive at least a first external clock signal from an external bus; clock generation circuitry, coupled to the clock receiver circuitry, to generate a first internal clock signal having a clock edge which is synchronized with the first external clock signal and to generate a second internal clock signal having a clock edge which is synchronized with the first external clock signal; a programmable register to store first identification information wherein the first identification information identifies the memory device; interface circuitry coupled to the external bus to receive a read request and second identification information; a first subarray section having a first internal I/O line to access data from a first memory cell location and a second internal I/O line to access data from a second memory cell location, wherein the first and second memory cell locations are in the first subarray section; a second subarray section having a first internal I/O line to access data from a third memory cell location and a second internal I/O line to access data from a fourth memory cell location, wherein the third and fourth memory cell locations are in the second subarray section; output driver circuitry, including a first output driver and a second output driver, to output data onto the external bus in response to the read request when the first identification information corresponds to the second identification information; and multiplexer circuitry, coupled to the output driver circuitry, wherein; the multiplexer circuitry couples the first internal I/O line of the first subarray section to an input of the first output driver and couples the first internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the first internal clock signal; and the multiplexer circuitry couples the second internal I/O line of the first subarray section to an input of the first output driver and couples the second internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the second internal clock signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A synchronous memory device having a memory cell array divided into a plurality of subarrays, including a first subarray and a second subarray wherein each subarray includes a plurality of subarray sections, the memory device comprises:
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clock receiver circuitry to receive at least a first external clock signal from an external bus; clock generation circuitry, coupled to the clock receiver circuitry, to generate a first internal clock signal having a clock edge which is synchronized with the first external clock signal and to generate a second internal clock signal having a clock edge which is synchronized with the first external clock signal; a device identification register to store an identification code to identify the memory device; interface circuitry coupled to the external bus to receive a read request and identification information; a first subarray section of a first subarray, the first subarray section having a first internal I/O line to access data from a first memory cell location and a second internal I/O line to access data from a second memory cell location, wherein the first and second memory cell locations are in the first subarray section; a second subarray section of a second subarray, the second subarray section having a first internal I/O line to access data from a third memory cell location and a second internal I/O line to access data from a fourth memory cell location, wherein the third and fourth memory cell locations are in the second subarray section; output driver circuitry, including a first output driver and a second output driver, to output data onto the external bus in response to the read request when the identification information corresponds to the identification code; and multiplexer circuitry, coupled to the output driver circuitry, wherein; the multiplexer circuitry couples the first internal I/O line of the first subarray section to an input of the first output driver and couples the first internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the first internal clock signal; and the multiplexer circuitry couples the second internal I/O line of the first subarray section to an input of the first output driver and couples the second internal I/O line of the second subarray section to an input of the second output driver in response to the clock edge of the second internal clock signal. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A memory system having a synchronous memory device coupled to a bus, the memory device having a programmable register to store an identification value and a memory cell array divided into a plurality of subarrays, wherein each subarray includes a plurality of subarray sections, the memory system comprises:
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clock receiver circuitry to receive a first bus clock from the bus; clock generation circuitry to generate a first clock edge which is synchronized with the first bus clock and to generate a second clock edge which is synchronized with the first bus clock; interface circuitry coupled to the bus to receive a read request and identification information wherein the interface circuitry includes comparison circuitry to determine if the identification information corresponds to the identification value stored in the programmable register; a first subarray section having a first data line to access data from a first memory cell location and a second data line to access data from a second memory cell location, wherein the first and second memory cell locations are in the first subarray section; a second subarray section having a first data line to access data from a third memory cell location and a second data line to access data from a fourth memory cell location, wherein the third and fourth memory cell locations are in the second subarray section; output drivers, including a first output driver and a second output driver, to output data onto the bus in response to the read request when the identification information corresponds to the identification value stored in the programmable register; and multiplexer circuitry, coupled to the output drivers, wherein; the multiplexer circuitry couples the first data line of the first subarray section to an input of the first output driver and couples the first data line of the second subarray section to an input of the second output driver in response to the first clock edge; and the multiplexer circuitry couples the second data line of the first subarray section to an input of the first output driver and couples the second data line of the second subarray section to an input of the second output driver in response to the second clock edge. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37)
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Specification