A 2.5-V, 72-Mbit DRAM based on packet protocol has been developed using 1)
a rotated hierarchical I/O architecture to reduce power noise and to minimi
ze the chip-size penalty associated with an 8-bit prefetch architecture imp
lemented with 16 internal banks and 144 I/O lines, 2) a delay-locked-loop c
ircuit using a high-speed and small-swing differential clock to achieve the
peak bandwidth of 2.0 GByte/s in a single chip with low noise sensitivity,
and 3) a flexible column redundancy scheme to efficiently increase redunda
ncy coverage using a shifted I/O line scheme for multibank architecture.