SEMICONDUCTOR MEMORY DEVICE THAT VARIES VOLTAGE LEVELS DEPENDING ON WHICH OF DIFFERENT MEMORY REGIONS THEREOF IS ACCESSED

摘要

A semiconductor memory device includes a semiconductor memory chip including a plurality of regions of memory cells, including a first memory region and a second memory region, and a memory controller configured to carry out a read of a memory cell in the first memory region by applying a first read voltage, and a read of a memory cell in the second memory region by applying a second read voltage that is different from the first read voltage.

主权项

1. A semiconductor memory device, comprising:
a semiconductor memory chip including a plurality of regions of memory cells, including a first memory region and a second memory region; and a memory controller configured to
set a first voltage based on a first number of times the first memory region has been accessed since a predetermined point of time and carry out an operation on memory cells of the first memory region by applying the first voltage, when the first number is more than a threshold number, andset a second voltage that is different from the first voltage based on a period of time that has passed since a last access to the second memory region and carry out the operation on memory cells of the second memory region by applying the second voltage, when a second number of times the second memory region has been accessed since the predetermined point of time is less than the threshold number.