A main power supply line and a main ground wiring provided to supply power from
one side (a first direction) of a memory region, a main power supply line and a
main ground wiring provided to supply the power from the other side (a second direction
opposite to the first direction) of the memory region are provided in a column
direction. A bit line driver arranged on one side is supplied with power from one
side, and a bit line driver arranged on the other side is supplied with the power
from the other side. As a result, no current path is formed in a region of the
power supply lines on the selected memory region.
