Semiconductor integrated circuit device

• US 5,978,305 A
• Filed: 10/02/1998
• Issued: 11/02/1999
• Est. Priority Date: 10/02/1997
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Hitachi, Ltd., Hitachi ULSI Systems Company Limited (Hitachi, Ltd.)
• Inventors: Sato, Jun, Miyamoto, Takashi, Yanagisawa, Kazumasa, Ayukawa, Kazushige, Tanaka, Yuji, Tanaka, Hitoshi, Sasaki, Toshio, Nakanishi, Satoru, Watanabe, Takao, Ohtsuka, Mariko
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): PHUNG, ANH K
• Application Number:
  US09/165,194
• Time in Patent Office: 396 Days
• Field of Search: 365/230.03, 365/230.02, 365/230.06, 365/200
• US Class Current: 365/230.03
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection

Abstract

A RAM mounted so as to mix with logic circuits has a plurality of memory mats and one control circuit provided for the plurality of memory mats. Arithmetic circuits for respectively performing +1 or -1 arithmetic operations are respectively provided so as to correspond to the respective memory mats and are electrically connected in cascade form. An input terminal of the initial-stage arithmetic circuit is supplied with address-setting fixed address signals. Input signals supplied to the next and subsequent arithmetic circuits or signals outputted therefrom are defined as own-assigned address signals (those assigned to the corresponding memory mats). A comparator provided in association with each arithmetic circuit referred to above makes comparisons for coincidence between the address signals and address signals input upon memory access. The corresponding memory mat is selected based on the resultant coincidence signal.

Claims

1. A semiconductor integrated circuit device comprising:

a plurality of mats; and

a control circuit which is commonly provided for said plurality of mats;

said plurality of mats each including,

a memory array;

an arithmetic circuit which adds a predetermined value to an input address signal or subtracts the same therefrom to form an output address signal; and

a comparator which determines coincidence or non-coincidence between either one of the input address signal or the output address signal and a mat selection signal commonly supplied to said plurality of mats; and

wherein a plurality of said arithmetic circuits corresponding to said plurality of mats are connected in cascade form, and

a corresponding memory array lying within a mat corresponding to said comparator having determined coincidence or non-coincidence is activated when the result of determination by said comparator shows a coincidence.

2. The semiconductor integrated circuit device according to claim 1, further comprising a common bit line which is commonly provided for said plurality of mats, and

wherein said memory arrays each comprise,

a plurality of word lines;

a plurality of bit lines;

a plurality of dynamic memory cells; and

a switch circuit which is provided between said bit lines and said common bit line.

3. The semiconductor integrated circuit device according to claim 1, wherein the number of said mats selected at one time by said mat selection signal is changeable by said control circuit and the memory arrays lying within said selected mats are activated.

4. A semiconductor integrated circuit device comprising:

a plurality of unit circuits respectively including,

memory arrays;

arithmetic circuits; and

determination circuits, and

wherein each arithmetic circuit adds a predetermined value to a signal inputted thereto or subtracts the same therefrom,

said plurality of arithmetic circuits in said plurality of unit circuits are connected in cascade form such that signals outputted from said respective arithmetic circuits are set as input signals for the following-stage arithmetic circuits,

said determination circuit determines coincidence or non-coincidence between either one of an input signal or an output signal of the corresponding arithmetic circuit and a selection signal commonly supplied to said plurality of unit circuits, and

when the result of determination by said determination circuit shows a coincidence, the corresponding memory array lying within the unit circuit corresponding to said determination circuit having determined coincidence or non-coincidence is activated.

5. The semiconductor integrated circuit device according to claim 4, further comprising a circuit which compares the magnitudes of a numeric value indicated by an input signal or an output signal of the final-stage arithmetic circuit of said plurality of arithmetic circuits connected in the cascade form and a numeric value indicated by the selection signal.

6. The semiconductor integrated circuit device according to claim 4, wherein the number of unit circuits selected at one time by the selection signal is changeable and the memory arrays lying within said selected unit circuits are activated.

7. A semiconductor integrated circuit device comprising:

a plurality of unit circuits each including,

an internal circuit block;

an arithmetic circuit; and

a comparator; and

wherein said each arithmetic circuit adds a predetermined value to a signal inputted thereto or subtracts the same therefrom,

said plurality of arithmetic circuits in said plurality of unit circuits are connected in cascade form such that signals outputted from said respective arithmetic circuits are set as input signals for the following-stage arithmetic circuits,

said comparator determines coincidence or non-coincidence between either one of an input signal or an output signal of the corresponding arithmetic circuit and a selection signal commonly supplied to said plurality of unit circuits, and

when the result of determination by said comparator shows a coincidence, the corresponding internal circuit block lying within the unit circuit corresponding to said comparator having determined coincidence or non-coincidence is activated.

8. The semiconductor integrated circuit device according to claim 7, wherein said internal circuit block includes a memory cell array, and further including a digital processing circuit which performs arithmetic operations, based on data read from said memory cell array.

9. The semiconductor integrated circuit device according to claim 7, wherein said predetermined value is +1.

10. A semiconductor integrated circuit device comprising:

a RAM module including,

a plurality of memory mats each including a memory array; and

a control circuit commonly provided for said plurality of memory mats;

said memory array including a plurality of word lines, a plurality of bit lines and a plurality of memory cells,

said plurality of memory mats each including,

an arithmetic circuit which performs +1 or -1 arithmetic operations on each of address-setting input signals comprised of a plurality of bits; and

a comparator which determines whether an input signal supplied to said arithmetic circuit or a signal outputted from said arithmetic circuit coincides with an address signal inputted upon memory access, and

wherein said arithmetic circuits in said plurality of memory mats are connected in cascade form, and

each memory mat activates an address selecting operation according to a signal indicative of the coincidence.

11. The semiconductor integrated circuit device according to claim 10, wherein the number of said memory mats is set according to the storage capacity of said RAM module.

12. The semiconductor integrated circuit device according to claim 10 or 11, wherein said memory cells comprise dynamic memory cells, and

each memory array includes at least one sense amplifier which reads and amplifies information stored in the memory cell to be read into each bit line and restores the electrical charge stored in the memory cell to the original state, a precharge circuit which precharges the potential on said bit line, and a column switch which connects the bit lines to a global bit line commonly provided for said plurality of memory mats.

13. The semiconductor integrated circuit device according to claim 12, wherein each memory mat includes first and second determination circuits for respectively determining coincidences between binary information assigned to each memory mat and bank address information commonly inputted to said plurality of memory mats, and validates X-system address signals used for a selecting operation of each word line or a result of decoding thereof, based on the result of determination by said first determination circuit, and validates Y-system address signals used for a selecting operation of each bit line or a result of decoding thereof, based on the result of determination by said second determination circuit, and

said control circuit supplies a bank setting signal for allowing said first determination circuit to forcefully make a coincidence decision according to the number of memory mats to be activated.

14. The semiconductor integrated circuit device according to claim 13, wherein an X-system address selection circuit for selecting each word line comprises,

a predecode circuit which divides X-system address signals into plural pairs and predecodes the divided plural pairs;

an AND-configured row decoder which includes series-connected MOSFETs for receiving the predecode signals outputted from said predecode circuit; and

a word driver which selects the corresponding word line in response to a word line selection signal formed by said row decoder, and

wherein the operation of said predecode circuit or row decoder is controlled based on the result of determination formed by said first determination circuit so that the corresponding word line selecting operation is performed by a selected memory mat.

15. The semiconductor integrated circuit device according to claim 10, further comprising an overflow check circuit which compares the magnitudes of an input signal supplied to the final-stage arithmetic circuit of said plurality of arithmetic circuits connected in cascade form or an output signal produced therefrom and each address signal inputted upon memory access of each memory mat, and

wherein the operation of a read amplifier for amplifying a read signal outputted from said memory mat is forcefully stopped according to an overflow detection signal detected by said overflow check circuit, and the overflow detection signal is transmitted to the outside of said RAM module.

16. The semiconductor integrated circuit device according to claim 11, wherein said control circuit further includes a detector which receives therein a signal outputted from the final-stage arithmetic circuit of said plurality of arithmetic circuits connected in cascade form and detects the number of mounted memory mats, and

said control circuit adjusts the load on each driver, which forms a control signal or a timing signal commonly supplied to said memory mats, so as to become substantially constant regardless of the number of the memory mats.

17. The semiconductor integrated circuit device according to claim 16, wherein each memory mat further includes dummy load circuits provided in a path for transmitting the control signal or the timing signal,

said control circuit designates the number of the dummy load circuits mounted to said respective memory mats, which are connected to said respective memory mats, and

said each memory mat is selectively connected to the corresponding dummy loads according to the control signal specified by said control circuit and the whole load on the driver is adjusted so as to become substantially constant regardless of the number of the memory mats.

18. The semiconductor integrated circuit device according to claim 16, wherein said control circuit further includes dummy load circuits provided at an output portion of a path for transmitting the control signal or the timing signal, and

said control circuit controls the number of the dummy load circuits connected to said respective memory mats so that the sum of the numbers of the mounted memory mats becomes equivalently identical to the maximum number of mounted memory mats, and controls the whole load on the driver for forming the control signal or timing signal so as to become substantially constant regardless of the number of the memory mats.

19. The semiconductor integrated circuit device according to claim 15, wherein said RAM module includes a control circuit and a plurality of memory mats arranged side by side in a straight line,

said arithmetic circuit in the memory mat provided at a position farthest from the control circuit is placed so as to be an initial-stage circuit and the arithmetic circuit in the memory mat disposed adjacent to the control circuit is placed so as to be a final-stage circuit, and

the overflow check circuit is provided in the control circuit or on the control circuit side, and a read amplifier for amplifying a read signal from each memory mat and a circuit for transmitting an overflow detection signal therefrom are placed in the control circuit.

20. The semiconductor integrated circuit device according to claim 16, wherein said RAM module includes a control circuit and a plurality of memory mats arranged side by side in a straight line,

said arithmetic circuit in the memory mat provided at a position farthest from the control circuit is placed so as to be an initial-stage circuit and said arithmetic circuit in the memory mat disposed adjacent to the control circuit is placed so as to be a final-stage circuit, and the number-of-memory mats detector provided in the control circuit is supplied with a signal outputted from the final-stage arithmetic circuit.

21. The semiconductor integrated circuit device according to claim 10, wherein said control circuit is supplied with row-system and column-system address signals separately, and

control circuit allows said each memory mat to perform row-system and column-system selecting operations in accordance with the separately-input row-system and column-system address signals.

22. The semiconductor integrated circuit device according to claim 21, wherein said row-system and column-system address signals are synchronized with a clock signal supplied from the outside of the RAM module and are inputted together with control signals which provide instructions for the operations of row-system and column-system circuits,

said address signals include address signals which select one or a plurality of memory mats, and

said instructions for the operation of said row-system circuit include two types of a start of the row-system selecting operation and an operation end for providing instructions for a precharge operation after the completion of the row-system selecting operation.

23. The semiconductor integrated circuit device according to claim 22, wherein when the immediately preceding state of said row-system circuit is said row-system selecting operation, said row-system circuit completes the previous operation and performs a precharge operation, and thereafter automatically performs a row-system selecting operation corresponding to the input address signals, whereas when the immediately preceding state thereof is said operation end state, said row-system circuit performs a row-system selecting operation corresponding to the input address signals.

24. The semiconductor integrated circuit device according to claim 22, wherein said RAM module has a reset input terminal and forcefully terminates the row-system and column-system selecting operations when a predetermined reset signal is inputted to said reset input terminal, whereby the selection circuit in each memory mat is brought to a precharge state.

25. The semiconductor integrated circuit device according to claim 12, wherein said RAM module is constructed such that in a state in which said semiconductor integrated circuit device is being supplied with a source voltage, the operation of each circuit is provided with the function of bringing it to a full standby state in which a current non-flowing state is held over a long time exceeding at least an information holding time of said each memory cell.

26. A semiconductor integrated circuit device comprising:

a plurality of circuit blocks each having a specific circuit function, said respective circuit blocks including,

arithmetic circuits which are respectively provided in said respective circuit blocks and perform +1 or -1 arithmetic operations on address-setting input signals comprised of a plurality of bits; and

comparators which respectively determine coincidences between input signals supplied to said arithmetic circuits or output signals produced therefrom and address signals, and

wherein the arithmetic circuits in said plurality of circuit blocks are connected in cascade form, the arithmetic circuit in the initial-stage circuit block has an input terminal supplied with fixed address signals, and the corresponding circuit block in respective circuit blocks is activated when a coincidence signal is outputted from said each comparator.