Semiconductor memory integrated circuit
View Patent ↗A semiconductor memory integrated circuit having an X-row controller which includes a high-speed-operation control circuit by which when receiving a bank active signal, a period for stopping a latch circuit from receiving the X address is produced after a predetermined time has elapsed, and in the other periods, the latch circuit receives and holds the X address; a low-current-operation control circuit by which when receiving no bank active signal, the latch circuit stops receiving the X address, and when receiving the bank active signal, the latch circuit holds the X address after a predetermined time has elapsed; a circuit for selecting whether the bank active signal is output to the high-speed-operation control circuit or the low-current-operation control circuit; and a circuit for selecting whether the latch-circuit control signal from the high-speed-operation control circuit or the latch-circuit control signal from the low-current-operation control circuit is output to the latch circuit.
1. A semiconductor memory integrated circuit comprising:
an X-row controller for reading an X address from an X-address signal line in the semiconductor memory integrated circuit, holding the X address in a latch circuit, and outputting the X address stored by the latch circuit to a predecoder selected by an bank active signal, wherein the X-row controller includes:
a high-speed-operation control circuit for generating and outputting a latch-circuit control signal, by which:
when the bank active signal is input into the high-speed-operation control circuit, an X-address reading stop period for stopping the latch circuit from receiving the X address is produced after a predetermined amount of delay time has elapsed from the input of the bank active signal, and
in the periods other than the X-address reading stop period, the latch circuit receives and holds the X address;
a low-current-operation control circuit for generating and outputting a latch-circuit control signal, by which:
when no bank active signal is input into the low-current-operation control circuit, the latch circuit stops receiving the X address, and
when the bank active signal is input into the low-current-operation control circuit, the latch circuit receives and holds the X address after a predetermined amount of delay time has elapsed from the input of the bank active signal;
an input switching circuit for selecting whether the bank active signal is output to the high-speed-operation control circuit or the low-current-operation control circuit in accordance with a switching signal input into the X-row controller; and
an output switching circuit for selecting whether the latch-circuit control signal output from the high-speed-operation control circuit or the latch-circuit control signal output from the low-current-operation control circuit is output to the latch circuit in accordance with the switching signal.
2. The semiconductor memory integrated circuit in accordance with claim 1 , wherein the semiconductor memory integrated circuit including the X-row controller is formed on a single chip.
3. The semiconductor memory integrated circuit in accordance with claim 1 , wherein the state of the switching signal input into the input switching circuit and the output switching circuit is determined by setting a mask pattern.
4. The semiconductor memory integrated circuit in accordance with claim 1 , wherein the state of the switching signal input into the input switching circuit and the output switching circuit is determined by making a laser fuse conduct or shut off the electricity.
5. The semiconductor memory integrated circuit in accordance with claim 1 , wherein the state of the switching signal input into the input switching circuit and the output switching circuit is determined by making an antifuse conduct or shut off the electricity.