I960 Architecture Documentation


DISCLAIMER: This documentation is derived from the cgen cpu description of this architecture, and does not represent official documentation of the chip maker.


In cgen-parlance, an architecture consists of machines and models. A `machine' is the specification of a variant of the architecture, and a `model' is the implementation of that specification. Typically there is a one-to-one correspondance between machine and model. The distinction allows for separation of what application programs see (the machine), and how to tune for the chip (what the compiler sees).
A "cpu family" is a cgen concoction to help organize the generated code. Chip variants that are quite dissimilar can be treated separately by the generated code even though they're both members of the same architecture.

I960 Architecture

This section describes various things about the cgen description of the I960 architecture. Familiarity with cgen cpu descriptions is assumed.

Bit number orientation (arch.lsb0?): msb = 0

ISA description

CPU Families

Machine variants

i960:ca - I960 CA processor

i960:ka_sa - I960 KA and SA processors

Model variants

i960CA - I960 CA processor

i960KA - I960 KA processor

Registers

h-cc - condition code

h-gr - general registers