FRV 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.

FRV Architecture

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

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

ISA description

CPU Families


Machine variants

fr400 - FR400 cpu

frv - Generic FRV cpu

simple - Simple single issue integer cpu

tomcat - Tomcat -- early version of fr500


Model variants

fr400 - FR400 model

frv - Generic FRV model

simple - Simple model

tomcat - Tomcat model


Registers

h-acc40S - 40 bit signed accumulator