Content-addresable circuit

Abstract

Abstract PURPOSE:To control partial comparative suppression to a word to be registered by providing a maskable content-addressable memory cell to suppress a comparing operation corresponding to comparative suppression information at one part of the train of content-addressable memory cells corresponding to the respective words of a content addressable memory. CONSTITUTION:The true value and complementary value of the input word are applied to digit lines 106 and 107 of the respective content addressable memory cells. When a data held at a latch R is matched with the data added from the paired lines 106, in a normal content addressable memory cell 103. Either a serial circuit composed of MOSTr T3 and T4 or a serial circuit com posed of MOSTr T5 and T6 is not conductive and therefore, the both circuits are not conducted. On the other hand, when the data is not matched, the T3 and T4 or the T5 and T6 are conducted together, and a matched word output line 105 is conducted to the ground. In a maskable cell 102, when the held value of a memory cell 101 is 0, the Tr T7 and T8 are not conducted and even when the data of the latch R and the data from paired lines 107 and not matched, there is no influence upon the output line 105. Thus, the comparing operation of the cell 102 is suppressed.

Inventors

• 👤 Hidetaka Oki
• 👤 沖　秀隆

Bibliographic Details