Programming Blitter

BLTCON

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ASH usea useb usec used LF BSH 0000 doff 00 efe ife fci desc 0

(normal mode)

  • ASH: shift value of source A
  • USEA: use source A
  • USEB: use source B
  • USEC: use source C
  • USED: use destination D
  • LF: performed logic function minterm select lines
  • BSH: shift value of source B
  • DOFF
  • EFE: exclusive fill
  • IFE: inclusive fill
  • FCI: fill carry input
  • DESC: descending address mode
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START 1 0 1 1 LF TEXTURE 0000 sign 00 sud sul aul sing 1

(line mode)

  • START: sttarting point of line
  • LF: performed logic function minterm select lines
  • TEXTURE:
  • SIGN: sign flag
  • SUD: sometimes up or down
  • SUL: sometimes up or left
  • AUL: always up or left
  • SING:single bit per horizontal line (for filling)

BLTSIZE, BLTSIZEV, BLTSIZEH

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h w
  • h: height in vertical lines
  • w: width in horizontal pixels

Blitter's Registers

BLTCON 040 2 words
BLTAFWM 044 word
BLTALWM 046 word
BLTCPT 048 2 words
BLTBPT 04E 2 words
BLTAPT 050 2 words
BLTDPT 054 2 words
BLTSIZE 058 word
BLTCONSIZV 05C word
BLTCONSIZH 05E word
BLTCMOD 060 word
BLTBMOD 062 word
BLTAMOD 064 word
BLTDMOD 066 word
/var/www/wiki/data/pages/hardware/blitter_programming_model.txt · Last modified: 2010/03/07 22:05 by gilgamesh
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