Semiconductor memory devices and memory systems including the same
A semiconductor memory device includes a control logic and a memory cell array in which a plurality of memory cells are arranged. The memory cell array includes a plurality of bank arrays, and each of the plurality of bank arrays includes a plurality of sub-arrays. The control logic controls an access to the memory cell array based on a command and an address signal. The control logic dynamically sets a keep-away zone that includes a plurality of memory cell rows which are deactivated based on a first word-line when the first word-line is enabled. The first word-line is coupled to a first memory cell row of a first sub-array of the plurality of sub-arrays. Therefore, increased timing parameters may be compensated, and parallelism may be increased.
1. A semiconductor memory device comprising:
a memory cell array in which a plurality of memory cells are arranged, the memory cell array including a plurality of bank arrays, each of the plurality of bank arrays including a plurality of sub-arrays; and
a control logic configured to control an access to the memory cell array based on a command and an address signal, the control logic being configured to calculate a distance from an activated first word-line based on a row address of the activated first word-line according to the address signal and dynamically set a region including a first memory cell row of a first sub-array among the plurality of sub-arrays within the distance from the activated first word-line as a keep-away zone,
wherein the keep-away zone includes a plurality of memory cell rows which are deactivated based on the first word-line when the first word-line is activated, and
wherein a first row cycle for the first word-line is at least partially overlapped with a second row cycle for a second word-line, the second word-line being coupled to a second memory cell row in a second sub-array among the plurality of sub-arrays, the second sub-array belonging to regions other than the keep-away zone.
2. The semiconductor memory device of claim 1 , wherein the control logic is configured to divide the plurality of sub-arrays into a plurality of sub-array groups based on at least one bit of the address signal, the plurality of sub-array groups including a first sub-array group, and
the control logic is configured to set sub-array groups adjacent to the first sub-array group including the first memory cell row as the keep-away zone.
3. The semiconductor memory device of claim 2 , wherein the control logic is configured to set the first sub-array group including the first memory cell row as an activated sub-array group.
4. The semiconductor memory device of claim 3 , wherein a size of each sub-array group is varied by a mode register set.
5. The semiconductor memory device of claim 3 , wherein a size of the activated sub-array group is varied by a mode register set.
6. The semiconductor memory device of claim 2 , wherein the at least one bit of the address signal is one or more upper bits of a row address of the address signal.
7. The semiconductor memory device of claim 1 , wherein a precharge time of the first row cycle is partially overlapped with a word-line enable time of the second row cycle.
8. The semiconductor memory device of claim 1 , further comprising a plurality of row decoders, each of the plurality of row decoders being coupled to a corresponding bank array among the plurality of bank arrays, each of the plurality of row decoders including:
a decoder configured to decode a row address of the address signal to provide a decoded row address; and
a plurality of word-line drivers, each of the plurality of word-line drivers being connected to a corresponding sub-array among the plurality of sub-arrays,
wherein the decoder is configured to commonly apply the decoded row address to the plurality of word-line drivers, and
the control logic is configured to commonly apply an active signal that selects each of the plurality of sub-arrays to the plurality of word-line drivers, and is configured to individually apply to the plurality of word-line drivers precharge signals that reset the plurality of word-line drivers.
9. The semiconductor memory device of claim 8 , wherein the active signal and the decoded row address are pulse-type signals.
10. The semiconductor memory device of claim 8 , wherein each of the plurality of word-line drivers comprises:
a first p-channel metal oxide semiconductor (PMOS) transistor coupled between a power supply voltage and a first node connected to a corresponding word-line;
a first n-channel metal oxide semiconductor (NMOS) transistor and a second NMOS transistor coupled in series between the first node and a ground voltage; and
a latch coupled to the corresponding word-line, the latch being configured to latch the active signal until the precharge signal is applied.
11. The semiconductor memory device of claim 10 , wherein the PMOS transistor has a gate that receives an inverted version of the precharge signal,
the first NMOS transistor has a gate that receives the active signal, and
the second NMOS transistor has a gate that receives the decoded row address.
12. A memory system comprising:
a semiconductor memory device configured to store data, the semiconductor memory device including:
a memory cell array including a plurality of bank arrays, each of the plurality of bank arrays including a plurality of sub-arrays; and
a control logic configured to control an access to the memory cell array based on a command and an address signal, the control logic being configured to calculate a distance from an activated first word-line based on a row address of the activated first word-line according to the address signal and dynamically set a region including a first memory cell row of a first sub-array among the plurality of sub-arrays within the distance from the activated first word-line as a keep-away zone; and
a memory controller configured to control the semiconductor memory device,
wherein the keep-away zone includes a plurality of memory cell rows which are deactivated based on the first word-line when the first word-line is activated.
13. The memory system of claim 12 , wherein a first row cycle for the first word-line is at least partially overlapped with a second row cycle for a second word-line, the second word-line being coupled to a second memory cell row in a second sub-array among the plurality of sub-arrays, the second sub-array belonging to regions other than the keep-away zone.
14. The memory system of claim 12 , wherein the semiconductor memory device is a dynamic random access memory (DRAM).
15. A memory device comprising:
a memory cell array including a plurality of bank arrays, each of the plurality of bank arrays including a plurality of sub-arrays;
an address register;
a row decoder;
a column decoder; and
a control logic configured to control an access to the memory cell array based on a command and an address signal, the control logic being configured to calculate a distance from an activated first word-line based on a row address of the activated first word-line according to the address signal and dynamically set a region including a first memory cell row of a first sub-array among the plurality of sub-arrays within the distance from the activated first word-line as a keep-away zone,
wherein the keep-away zone includes a plurality of memory cell rows which are deactivated based on the first word-line when the first word-line is activated, and
wherein the control logic is configured to access the first memory cell row and a second memory cell row by partially overlapping a first row cycle for the first word-line with a second row cycle for a second word-line, the second word-line being coupled to the second memory cell row of a second sub-array among the plurality of sub-arrays, the second sub-array being in an overlappable region other than the keep-away zone.
16. The memory device of claim 15 , wherein the control logic is configured to divide the plurality of sub-arrays into a plurality of sub-array groups, the plurality of sub-array groups including a first sub-array group, and
the control logic is configured to set sub-array groups adjacent to the first sub-array group including the first memory cell row as the keep-away zone.
17. The memory device of claim 15 , wherein a precharge time of the first row cycle is partially overlapped with a word-line enable time of the second row cycle.