2009/2/26 Juan Erbes
El día 26 de febrero de 2009 0:41, Carlos E. R.
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Yo no sé quien hizo primero un procesador de uso general de 32 bits, pero con los datos que has puesto no me convences que fuera AMD.
Segun uno de los links citados, el micro X86 K5 de 32 bits de AMD, derivaba directamente de los risc de la serie 29XXX: The 29000 has 64 global registers, in comparison to the SPARC's eight. In addition, the 29000 allows variable sized windows allocated from the 128 register stack cache. The current window or stack frame is indicated by a stack pointer (a modern version of the ISAR register in the Fairchild F8 CPU), a pointer to the caller's frame is stored in the current frame, like in an ordinary stack (directly supporting stack languages like C, a CISC-like philosophy). Spills and fills occur only at the ends of the cache, and registers are saved/loaded from the memory stack. This allows variable window sizes, from 1 to 128 registers. This flexibility, plus the large set of global registers, makes register allocation easier than in SPARC (optimised stack operations also make it ideal for stack-oriented interpreted languages such as PostScript, making it popular as a laser printer controller).
There is no special condition code register - any general register is used instead, allowing several condition codes to be retained, though this sometimes makes code more complex. An instruction prefetch buffer (using burst mode) ensures a steady instruction stream. Branches to another stream can cause a delay, so the first four new instructions are cached - next time a cached branch (up to sixteen) is taken, the cache supplies instructions during the initial memory access delay.
Registers aren't saved during interrupts, allowing the interrupt routine to determine whether the overhead is worthwhile. In addition, a form of register access control is provided. All registers can be protected, in blocks of 4, from access. These features make the 29000 useful for embedded applications, which is where most of these processors are used, allowing it at one point to claim the title of 'the most popular RISC processor'. The 29000 also includes an MMU and support for the 29027 FPU. The superscalar 29050 version in 1990 integrated a redesigned FPU (4 instructions could be dispatched to execute out of order and speculatively).
In late 1995 Advanced Micro Devices dropped development of the 29K in favour of its more profitable clones of Intel 80x86 processors, while Intel tried to replace the x86 with an architecture similar to the 29K, although much of the development of the superscalar core for a new AMD 29000 (including FPU designs from the 29050) was shared with the 'K5' (1995) Pentium compatible processor (the 'K5' translates 80x86 instructions to RISC-like instructions, and dispatches up to five at once to two integer units, one FPU, a branch and a load/store unit).
Por ejemplo, Motorola hacía el 68000, que es de 32 bits (bus externo de datos de 16 bits), fabricado en el 1980. En 1984 fabricaban el 68020, con bus externo de 32.
Gracias a los procesadores de la linea 68xxx, fue que se impusieron las computadoras Apple y Commodore Amiga, que fueron las primeras computadoras multimedia, con las que se pudo comenzar a edicion de video digital, mientras que las basadas en intel, ni siquiera tenian sonido (salvo el pc speaker de onda cuadrada)
Aparte de que ese procesador que has citado (no has puesto el número exacto) no parece de propósito general:
El numero por el que preguntaba por el año de fabricación, era el Am29325, que venia con bus de 32 bits externo, subdivisible en 2 de 16.
Salu2 --
Muy bueno el resto ... Un saludo -- Octavio Ávalos -- Para dar de baja la suscripción, mande un mensaje a: opensuse-es+unsubscribe@opensuse.org Para obtener el resto de direcciones-comando, mande un mensaje a: opensuse-es+help@opensuse.org