摘要 |
<p>A multi-bank DRAM has a hierarchical column select line architecture. The DRAM is provided with a plurality of memory cells which are organised in at least two banks. Each of the banks includes memory cells which are arranged in rows and columns. The memory cells store data provided by at least one bit line and at least one data line. The DRAM includes: a first switch for selecting one of the two banks; and a second switch connected to the first switch for selecting one of the columns, wherein the first and second switches couple one of the bit lines to one of the data lines, enabling data to be written into or read out of memory cells common to the selected bank and to the selected column. The first switch is controlled by a plurality of bank CSLs (BCSLs), wherein the BCSLs are shared by some of the blocks within the same bank, but not by any of the blocks in other banks. The second switch is controlled by a plurality of global CSLs (GCSLs), the GCSLs being shared by all remaining banks within a unit. The BCSLs and GCSLs are controlled by the bank column decoder and by the global column decoder. <IMAGE></p> |