FNX6809 Manuals: Difference between revisions

From F256 Foenix
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'''ACT_LUT''' these two bits specify which MLUT (0–3) is used to translate CPU bus address to system bus addresses.
'''ACT_LUT''' these two bits specify which MLUT (0–3) is used to translate CPU bus address to system bus addresses.


'''EDIT_LUT''' these two bits will specify which MLUT (0 - 3) is being edited and will appear in memory addresses 0x0008–0x0010.
'''EDIT_LUT''' these two bits will specify which MLUT (0 - 3) is being edited and will appear in memory addresses $FFA8-$FFAF.
 
These locations are defined in nitros9/defs/f256.d:
 
MMU_MEM_CTRL    equ       $FFA0
 
MMU_IO_CTRL        equ       $FFA1
 
MMU_SLOT_0          equ       $FFA8               $0000-$1FFF
 
MMU_SLOT_1          equ       $FFA9               $2000-$3FFF
 
MMU_SLOT_2          equ       $FFAA               $4000-$5FFF
 
MMU_SLOT_3          equ       $FFAB               $6000-$7FFF
 
MMU_SLOT_4          equ       $FFAC               $8000-$9FFF
 
MMU_SLOT_5          equ       $FFAD               $A000-$BFFF
 
MMU_SLOT_6          equ       $FFAE               $C000-$DFFF
 
MMU_SLOT_7          equ       $FFAF               $E000-$FFFF


== Memory Map ==
== Memory Map ==

Revision as of 21:18, 31 May 2024

MMU Registers

Address R/W Name 7 6 5 4 3 2 1 0
$FFA0 RW MMU_MEM_CTRL - - EDIT_LUT - - ACT_LUT
$FFA1 RW MMU_IO_CTRL - - - - - $FFF0-$FFFF

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$FD00-$FDFF

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There are 4 MLUTs (MMU Lookup Tables).

ACT_LUT these two bits specify which MLUT (0–3) is used to translate CPU bus address to system bus addresses.

EDIT_LUT these two bits will specify which MLUT (0 - 3) is being edited and will appear in memory addresses $FFA8-$FFAF.

These locations are defined in nitros9/defs/f256.d:

MMU_MEM_CTRL    equ       $FFA0

MMU_IO_CTRL        equ       $FFA1

MMU_SLOT_0          equ       $FFA8               $0000-$1FFF

MMU_SLOT_1          equ       $FFA9               $2000-$3FFF

MMU_SLOT_2          equ       $FFAA               $4000-$5FFF

MMU_SLOT_3          equ       $FFAB               $6000-$7FFF

MMU_SLOT_4          equ       $FFAC               $8000-$9FFF

MMU_SLOT_5          equ       $FFAD               $A000-$BFFF

MMU_SLOT_6          equ       $FFAE               $C000-$DFFF

MMU_SLOT_7          equ       $FFAF               $E000-$FFFF

Memory Map

Memory Model