View source for User:Myask/Universal Mapper Description Language

=Needed features=
Been thinking about making some better way to talk about mappers, as described [http://forums.nesdev.org/viewtopic.php?p=74174#p74174 in this post] among several other places on our boards.
Parts/functions
* Define state bits
** include easy ROM/RAM chip(/internal) declaration; don't want to exclude MagicFloor nor MMC5/6 from "correct" description
* Logic
* Arbitrary address bus size for chips?
Convenience addtions
* Conditional operations (optional but helps user-side…but makes it harder program-side)
** some header fields as parameters might be desirable (mirroring, chip sizes)
** on the other hand, they are different boards in some manner. Perhaps only as solder-pad options?
* [[Cartridge connector]] pins as predefined signal names, or a module (to allow picking 60 or 72-pin)
* Option to autoconnect power, ground, address lines that are not in file 
**<nowiki> like connecting PPU_A[0:7] to CHR_ROM_A[0:7] if CHR_ROM_A[0:7] do not appear in the description)</nowiki>
** Also autoconnect CIC
Extra function thoughts
* Outputs (e.g. LED)
* Inputs (e.g. DIPswitch, solder pads)
* Describing expansion port devices in similar manner
* Describing controller port devices in similar manner
Hard Part
* Expansion audio (analog, can involve extra oscillators as [[VRC7 audio]] does)

=[[NROM]]-256 example=
 mapper NROM_256V begin
  //without autofills
 //component section
  prgrom prg(32KiB); 
  //could also write 256Kib..but seems like a source of many typo problems
  //perhaps go by address line, data line counts?
  chrrom chr(8KiB);
  //only difference between PRG and CHR def'ns are its default connections
  //and outputs
  CIC cic(NES);//allow other chips I guess?
 
 //dynamic components section
  solder h to connect CIRAM_A10 to PPU_A[10];
  solder v to connect CIRAM_A10 to PPU_A[11]; 
  init h iNES.6[0];
  init v ~iNES.6[0];
   //technically redundant per wiki as only V-using boards had solder pads?
   //make "to" as whitespace, allowing nice codelook but not requiring 
  connect CIRAM_CE_n to PPU_A13_n;
 
 //connections: power
  connect VCC prg.vcc cic.vcc chr.vcc;
  connect GND prg.gnd cic.gnd chr.gnd;
   //allow multiple connections per statement
   //considering a shortform lke "=" for connect
 //connections: CIC 
  //[omitted]
 //connections: PRG
  connect prg.a[14:0] CPU_A[14:0];
  //NROM_128: connect prg.a[13:0] CPU_A[13:0];
  //and connect prg.a[14] VCC; //several ways to do it, really.
  connect prg.d[7:0] CPU_D[7:0];
  connect prg.oe_n prg.ce_n ROMSEL_n; //I suspect I've got these mildly wrong
 //connections: CHR
  connect chr.a[12:0] PPU_A[12:0];
  connect chr.d[7:0] PPU_D[7:0];
  connect chr.oe_n chr.ce_n PPU_A[13];
 
 end NROM_256V;