Conventions used in MicroCore Code

1. Version numbering

   Version numbers are composed of an identifier 3 (released version) or 4 (prerelease version) digits long to identify a specific MicroCore. A '.' is inserted between the first and second position. Each character position has its own semantic and is counted up starting from 0, 1 .. 9 followed by A, B etc.

   • 1st position Substantial functional change. Versions which differ in this position can be expected to be no longer source code compatible.
   • 2nd position Functional extension. New instructions added.
   • 3rd position Bug fixes
   • 4th position Prerelease digit. Version numbers with 4 digits are experimental versions. This 3 or 4 digit identifier may be followed by multiple _ attachments which stand for functional capabilities added to the I/O bus.

   Examples:
   1.00 First released version of MicroCore
   1.01 Released version after first bug fix with debug interface added.
   1.100_fpgabus Experimental version with e.g. a new instruction and an FPGAbus interface added.
   

2. VHDL source code

   All VHDL keywords have been written in upper case, all aplication specific names in lower case. I find it more readable this way.

   For identifiers, the following conventions have been used:

   Identifier	Semantics
   <name>_addr	Address
   <name>_ctr	Counter
   <name>_en	Enable signal
   <name>_i	Internal signal which corresponds to signal <name>, which is an OUT signal in the entity.
   <name>_in	Input signal. Only used to clarify a signal name and its direction.
   <name>_out	Output signal. Only used to clarify a signal name.
   <name>_reg	Register
   s_<name>	Status register bit
   c_<name>	Control register bit
   sel_<name>	Select signal