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The RCA CDP1802, also known as the COSMAC (''Complementary Symmetry Monolithic Array Computer''), is an 8-bit CMOS microprocessor (µP) introduced by RCA in early 1976. It is being (manufactured ) by Intersil Corporation as a high-reliability microprocessor. The 1802 has an architecture different from most other 8-bit microprocessors. In 1970 and 1971, Joseph Weisbecker developed a new 8-bit architecture computer system,.〔''An Eight-Bit Micro-Processor'', RCA Technical Report, PRRL-7l-TR-207〕 RCA released Weisbecker's work as the COSMAC 1801R and 1801U in early 1975, using its CMOS process (called ''COSMOS'', an acronym for ''Complementary Silicon/Metal-oxide Semiconductor''). In 1976, a team led by Jerry Herzog integrated the two chips into one, the 1802.〔〔(【引用サイトリンク】title=Joseph A. Weisbecker (1932 - 1990) )〕 == Introduction == The RCA 1802 has a static core CMOS design with no minimum clock frequency, so that it can be run at very low speeds and low power. It has two separate 8-pin buses: an 8-bit bidirectional data bus and a multiplexed address bus (i.e., the high order byte of the 16-bit address and the low order byte of the address take turns in using the 8-bit physical address bus lines, by accessing the bus lines in different clock cycles). The RCA 1802 has a single bit, programmable output port, and four input pins which are directly tested by branch instructions. Its I/O mode is flexible and programmable, and it has a single-phase clock with an on-chip oscillator. Its register set consists of sixteen 16-bit registers. The program counter (PC) can reside in any of these, providing a simple way to implement multiple PCs, pointers, or registers. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「RCA 1802」の詳細全文を読む スポンサード リンク
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