摘要:
In a nonvolatile memory cell having a trap layer, by executing first charge injection with a given wait time being secured and second charge injection after the first charge injection in a programming or erasing sequence, surrounding charge that may deteriorate the data retention characteristic is reduced utilizing an initial variation (charge loss phenomenon caused by binding of injected charge with the surrounding charge in an extremely short time) occurring immediately after programming. Thereafter, the charge loss in the initial variation is compensated, so that the subsequent data retention characteristic is improved. The second charge injection is executed only when a predetermined determination level has been reached.
摘要:
In a nonvolatile memory cell having a trap layer, programming or erasing is made in a sequence of first charge injection with a given wait time being secured and second charge injection executed after the first charge injection. Surrounding charge that deteriorates the data retention characteristic is reduced by use of initial variation occurring immediately after programming (charge loss phenomenon due to binding of injected charge with the surrounding charge in an extremely short time), and then the charge loss due to the initial variation is compensated, to thereby improve the data retention characteristic.
摘要:
In a nonvolatile memory cell having a trap layer, programming or erasing is made in a sequence of first charge injection with a given wait time being secured and second charge injection executed after the first charge injection. Surrounding charge that deteriorates the data retention characteristic is reduced by use of initial variation occurring immediately after programming (charge loss phenomenon due to binding of injected charge with the surrounding charge in an extremely short time), and then the charge loss due to the initial variation is compensated, to thereby improve the data retention characteristic.
摘要:
An electronic equipment system includes a semiconductor integrated circuit having a nonvolatile memory storing information on a characteristic of the semiconductor integrated circuit; and a controller configured to control the semiconductor integrated circuit. The controller has a function of adjusting an access parameter to the semiconductor integrated circuit based on the information stored in the nonvolatile memory.
摘要:
Even when the number of rewrite operations varies among erase unit areas, the number of rewrite operations is improved for all of the erase unit areas. A flash EEPROM 100 comprises a trimming value storing area 130 of storing a trimming value corresponding to each erase unit area 120 included in a memory cell array 110. When an erase operation and a write operation are performed with respect to a certain erase unit area 120, a regulator circuit 150 converts a voltage boosted by a booster circuit 140 to a level corresponding to the trimming value for the erase unit area 120. When a read determination circuit 170 detects an abnormality as the number of rewrite operations is increased, the trimming value is updated to a value which causes the regulator circuit 150 to increase the output voltage.
摘要:
A writing operation selecting circuit is provided for selecting a temporary writing operation having a prescribed writing time for a memory cell transistor element and an additional writing operation for the memory cell transistor element. A writing time control circuit is provided for controlling an additional writing operation time by an output signal of the writing operation selecting circuit.
摘要:
A semiconductor integrated circuit system comprises a semiconductor memory device including a memory cell array having a plurality of memory cells; a monitor circuit for monitoring characteristics of the memory cells; and a voltage output circuit connected to the semiconductor memory device to supply a power supply voltage to the semiconductor memory device; the voltage output circuit being configured to change an output voltage according to an output of the monitor circuit.
摘要:
A writing operation selecting circuit is provided for selecting a temporary writing operation having a prescribed writing time for a memory cell transistor element and an additional writing operation for the memory cell transistor element. A writing time control circuit is provided for controlling an additional writing operation time by an output signal of the writing operation selecting circuit.
摘要:
An electronic equipment system includes a semiconductor integrated circuit having a nonvolatile memory storing information on a characteristic of the semiconductor integrated circuit; and a controller configured to control the semiconductor integrated circuit. The controller has a function of adjusting an access parameter to the semiconductor integrated circuit based on the information stored in the nonvolatile memory.
摘要:
A memory controller outputs an additional writing instruction to one of a plurality of non-volatile memories arbitrarily selected via a writing instruction output unit when a signal which rejects a writing operation is not outputted from writing controllers of the plurality of non-volatile memories for a certain period of time, and outputs a temporary writing instruction to another non-volatile memory at least once via the writing instruction output unit by the time when the additional writing operation is completed in the arbitrary non-volatile memory.