NEO-E0: Difference between revisions

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=[[System ROM]] vector table swapping=
=68k vector table swapping=
When 68k A8~A23 = 0 and the [[System ROM]]'s vector table is chosen (by using {{Reg|REG_SWPBIOS}} or {{Reg|REG_SWPROM}}), A22I~A23I outputs are set to 1.  This makes the address appear to address decoding chips as a system ROM access instead of a [[P ROM]] access.
The 68k vector table is swapped with the [[System ROM]] one by using {{Reg|REG_SWPBIOS}} or {{Reg|REG_SWPROM}}.
 
A22I~A23I are used to make the address appear to address decoding chips as a system ROM access instead of a [[P ROM]] access.
 
{|class="wikitable"
!rowspan=2|Address||colspan=2|Maps to
|-
!VEC = 0||VEC = 1
|-
|$000000~$0000FF||$C00000~$C000FF||$000000~$0000FF
|-
|$000100~$BFFFFF||colspan=2|$000100~$BFFFFF
|-
|$C00000~$C000FF||$000000~$0000FF||$C00000~$C000FF
|-
|$C00100~$FFFFFF||colspan=2|$C00100~$FFFFFF
|}


[[User:Kyuusaku]]: {A23Z,A22Z} = A[23:22] ^ 2{~|{A[21:7],^A[23:22],VEC}}
[[User:Kyuusaku]]: {A23Z,A22Z} = A[23:22] ^ 2{~|{A[21:7],^A[23:22],VEC}}
On the AES, the AND gate is used to get /SROMOE from /SROMOEL AND /SROMOEU.


=Pinouts=
=Pinouts=

Revision as of 08:15, 19 February 2017

Package QFP64R
Manufacturer
First use 1991 ?
Used on NEO-AES3-3 ...

68k vector table swapping

The 68k vector table is swapped with the System ROM one by using REG_SWPBIOS or REG_SWPROM.

A22I~A23I are used to make the address appear to address decoding chips as a system ROM access instead of a P ROM access.

Address Maps to
VEC = 0 VEC = 1
$000000~$0000FF $C00000~$C000FF $000000~$0000FF
$000100~$BFFFFF $000100~$BFFFFF
$C00000~$C000FF $000000~$0000FF $C00000~$C000FF
$C00100~$FFFFFF $C00100~$FFFFFF

User:Kyuusaku: {A23Z,A22Z} = A[23:22] ^ 2{~|{A[21:7],^A[23:22],VEC}}

Pinouts

MV2B @ H7 pinout

55 = sPCK1B 56 = sPCK2B

MV2B @ G2 pinout

OpenOffice Draw file: File:Neo-e0 mv2b G2.odg

MV2B @ F7 pinout

OpenOffice Draw file: File:Neo-e0 mv2b F7.odg

Acts just as a buffer.

  • s*: signals to both slots

Pinout

OpenOffice Draw file: File:Neo-e0.odg

  • A1~A23: 68k address bus
  • Y0~Y23: memory card address bus
  • BNK0~BNK2: comes from NEO-D0, memory card banking
  • VEC: System ROM vector table swapping enable
  • ANI0, ANI1, AND0: AND gate used to generate ROMOE from ROMOEU and ROMOEL