Semiconductor device having nonvolatile memory element and data processing system including the same
View Patent ↗A semiconductor device includes a fuse element, a read-out circuit that reads out a memory content of the fuse element in response to a first internal reset signal that is activated in response to transition of an external reset signal, and a latch circuit that holds therein the memory content read out by the read-out circuit and is reset by a second internal reset signal that is activated based on an activation period of the external reset signal. With this configuration, even when the activation period of the external reset signal is long, the time for which a current flows through the fuse element can be shortened, thereby making it possible to reduce a current consumption at the time of a reset operation.
1. A semiconductor device comprising:
a timing control circuit producing first and second reset signals, the first reset signal taking an active level during the second reset signal taking an inactive level, and the second reset signal taking an active level during the first reset signal taking an inactive level;
an information storing element;
a read-out circuit coupled to the timing control circuit and the information storing element and activated in response to the active level of the first reset signal to read out information stored in the information storing element; and
an SR latch circuit including a set terminal supplied with an output from the read-out circuit and a reset terminal supplied with the second reset signal, the SR latch circuit being cleared in response to the active level of the second reset signal.
2. The device as claimed in claim 1 , wherein the read-out circuit comprises an additional latch circuit that temporarily holds information read out from the information storing element and supplies the information to the set terminal of the SR latch circuit.
3. The device as claimed in claim 2 , wherein the timing control circuit receives an original reset signal to produce the first and second reset signals.
4. The device as claimed in claim 3 , wherein the timing control circuit comprises a one-shot pulse circuit which produces the first reset signal as a one-shot pulse in response to a change of the original reset signal from a first logic level to a second logic level.
5. The device as claimed in claim 3 , wherein the timing control circuit comprises a delay circuit which produces the second reset signal by delaying the original reset.
6. The device as claimed in claim 3 , wherein the timing control circuit comprises a one-shot pulse circuit which produces the first reset signal as a one-shot pulse in response to a change of the original reset signal from a first logic level to a second logic level, the timing control circuit further comprising a delay circuit which produces the second reset signal by delaying the original reset.
7. The device as claimed in claim 6 , wherein the second logic level of the original reset signal corresponds to the active level of the second reset signal and the one-shot pulse takes the active level of the first reset signal.
8. A semiconductor device comprising:
a timing control circuit producing first and second reset signals, the first reset signal taking an active level during a first period of time, the second reset signal taking an active level during a second period of time;
an information storage element;
a read-out circuit coupled to the timing control circuit and the information storage element and activated in response to the active level of the first reset signal to read out information stored in the information storage element and produce an output signal related to the information; and
a latch circuit including a first input terminal and a second input terminal provided independently of the first input terminal, the first input terminal being coupled to the read-out circuit to receive the output signal from the read-out circuit, the second input terminal being coupled to the timing control circuit to receive the second reset signal, the latch circuit being cleared in response to the active level of the second reset signal.
9. The device as claimed in claim 8 , wherein the read-put circuit comprises an additional latch circuit that temporarily stores the information and produces the output signal.
10. The device as claimed in claim 9 , wherein the first period is smaller than the second period.
11. The device as clamed in claim 10 , wherein the first period appears while the second reset signal is taking an inactive level and the second period arrears while the first reset signal is taking an inactive level.
12. The device as claimed in claim 9 , wherein the at least a part of the first period overlaps with at least a part of the second period.
13. The device as claimed in claim 9 , wherein the timing control circuit produces the first and second reset signals in response to an original reset signal, the original reset signal changing between an active level and an inactive level.
14. The device as claimed in claim 13 , wherein the first reset signal is produced in response to a change from one of the active and inactive levels to the other of the active and inactive levels of the original reset signal, and the second period is approximately equal to a period time when the original reset signal is taking one of the active and inactive levels.
15. The device as claimed in claim 9 , further comprising a power-on circuit that produces a power-on signal in response to switch-on of a power supply voltage to the device, the timing control circuit receiving the power-on signal to produce the first reset signal.
16. A semiconductor device comprising:
a timing control circuit producing first and second reset signals, the first reset signal taking an active level during a first period of time, the second reset signal taking an active level during a second period of time;
a storage circuit comprising,
an information storage element,
a read-out circuit coupled to the timing control circuit and the information storage element and activated in response to the active level of the first reset signal to read out information stored in the information storage element,
a first latch circuit temporarily storing the information and producing an output signal related to the information, and
a second latch circuit including a first input terminal and a second input terminal provided independently of the first input terminal, the first input terminal being coupled to the first latch circuit to receive the output signal, the second input terminal being coupled to the timing control circuit to receive the second reset signal, the second latch circuit being cleared in response to the active level of the second reset signal; and
a main circuit performing a circuit operation in response to an output of the latch circuit.
17. The device as claimed in claim 16 , wherein the information storage element comprises a fuse, and the output signal indicates that the fuse is in one of a blown state and a non-blown state.
18. The device as claimed in claim 16 , wherein the main circuit comprises a memory circuit and performs a data read and write operations on the memory circuit in response to the output from the latch circuit.
19. The device as claimed in claim 17 , wherein the main circuit comprises a memory circuit and performs a data read and write operations on the memory circuit in response to the output from the latch circuit.