[wiki:Component SocLib Components General Index] 

!!!! UNDER CONSTRUCTION !!!!

= ST231 Processor Functional Description =

The ST231 processor core is an hardware component implementing a 7-stage VLIW processor  with register scoreboarding and 32-bit x 32-bit multiplies for integer and fractional data representations. 
Though a MMU was also added so the ST231 can be used as a host processor, this processor is mostly used in digital video consumer electronics.

This component is an ISS, which should be wrapped with an [wiki:Component/IssWrapper IssWrapper] for integration into a complete platform.

This instruction set simulator acts as a slave to the [wiki:Component/IssWrapper IssWrapper] and is organised identically to the
other Isses available within the library.

= Component definition =

Available in source: trunk/soclib/soclib/lib/st231/metadata/st231.sd

== Usage ==

ST231 has no parameters.
{{{
Uses( 'microblaze')
}}}

= Microblaze Processor ISS  Implementation =

The implementation is in 
 * source:trunk/soclib/soclib/lib/src/iss/microblaze.h
   This defines the resources associated to the MicroBlaze along with a few
   minimal helper functions (or methods, as they call them)
 * source:trunk/soclib/soclib/lib/src/iss/microblaze.cpp
   This is a large switch (as opposed to calling insn execution through
   pointers to functions) and a few macros, as it is overall not worse to
   traverse a switch than to move from tag to tag, seen the context necessary
   to the execution of one instruction (at least in the MicroBlaze case).

It is possible to compile a version of the MicroBlaze that issues the instruction
address along with the instruction being executed by defining `MBDEBUG` at `1` line
35 of source:trunk/soclib/soclib/lib/src/iss/microblaze.cpp
This is quite useful to check that the processor is really interpreting correctly a
sequence of instructions.
The MicroBlaze model is now able to connect to the GDB stub, so it is possible to
use GDB for debugging software running on it.

== Template parameters ==
 
This component has no template parameters.

== Constructor parameters ==

{{{
ST231iss(
    uint32_t ident       // processor id
);
}}}

== Ports ==

The `IssWrapper` module is in charge of defining the communication ports.