Latest revision as of 07:19, 18 July 2022


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

Just a 24-bit buffer and logic for 68k vector table swapping.

68k vector table swapping

The 68k vector table seen by the 68k is selected by writing to REG_SWPROM (table from the game) or REG_SWPBIOS (table from the system ROM).

A22Z and A23Z are used in place of A22 and A23 to make the address appear to address decoding chips as a system ROM access instead of a P ROM access.

The VEC signal comes from the 74H259 system latch.

Address	Maps to
Address	VEC = 0	VEC = 1
$000000~$00007F	$C00000~$C0007F	$000000~$00007F
$000080~$BFFFFF	No change
$C00000~$C0007F	$000000~$00007F	$C00000~$C0007F
$C00080~$FFFFFF	No change

Verilog from User:Kyuusaku:

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

Pinouts

Input to output map

64 -> 5
1 -> 6
2 -> 7
3 -> 8
4 -> 9
15 -> 11
16 -> 12
17 -> 13
18 -> 14
19 -> 22
20 -> 23
21 -> 24
31 -> 27
32 -> 28
33 -> 29
34 -> 30
36 -> 39
37 -> 40
38 -> 41
48 -> 43
49 -> 44
50 -> 45
51 -> 46
52 -> 47
53 -> 55 if VEC is high
54 -> 56 if VEC is high

Console

On the AES, the AND gate is used to make /SROMOE from (/SROMOEL AND /SROMOEU).

MV2B & MV2-01 @ H7 pinout

55 = sPCK1B
56 = sPCK2B

P_bus buffer

MV2B @ G2 pinout

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

A1~A23: 68k address bus
MCA0~MCA23: memory card address bus
BNK0~BNK2: memory card banking from NEO-D0
VEC: System ROM vector table swapping enable

MV2B @ F7 pinout

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

Acts just as a buffer.

s*: signals to both slots

MV2F @ E1 pinout (to be confirmed) and AES

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 bank
VEC: System ROM vector table swapping
ANI0, ANI1, AND0: AND gate used to generate ROMOE from (ROMOEU and ROMOEL)

@@ Line 1: / Line 1: @@
-[[File:aes_e0.jpg|right|thumb|NEO-E0 chip found on a AES board.]]
+{{ChipInfo
+|picture=aes_e0.jpg
+|pkg=QFP64R
+|manu=fujitsu
+|date=1991 ?
+|gates=
+|used_on={{PCB|NEO-AES3-3}} ...
+}}
-Also found on MVS boards, even those without memory card slots.
+Just a 24-bit buffer and logic for [[68k vector table]] swapping.
-==BIOS vector table swapping==
+=68k vector table swapping=
-When 68k A8~A23 = 0 and the [[BIOSes|BIOS]]'s vector table is chosen (by using the "system" [[memory mapped registers#System registers|memory mapped registers]]), A22I~A23I outputs are set to 1.  This makes the address appear to address decoding chips as a BIOS access instead of a [[P ROM]] access.
+The 68k vector table seen by the 68k is selected by writing to {{Reg|REG_SWPROM}} (table from the game) or {{Reg|REG_SWPBIOS}} (table from the [[system ROM]]).
-==Memory card address latch==
+A22Z and A23Z are used in place of A22 and A23 to make the address appear to address decoding chips as a system ROM access instead of a [[P ROM]] access.
-On AES systems, BNK0~BNK2 are tied low. This makes the chip act just like a buffer ?
-What are BNK0~BNK2 used for ?
+The {{Sig|VEC|VEC}} signal comes from the 74H259 system latch.
-The chip also ANDs the pair of 8bit output enable signals from the [[NEO-C1]] since there is only a single 16bit ROM used for the BIOS.
+{|class="wikitable"
+!rowspan=2|Address||colspan=2|Maps to
+|-
+!VEC = 0||VEC = 1
+|-
+|$000000~$00007F||$C00000~$C0007F||$000000~$00007F
+|-
+|$000080~$BFFFFF||colspan=2|No change
+|-
+|$C00000~$C0007F||$000000~$00007F||$C00000~$C0007F
+|-
+|$C00080~$FFFFFF||colspan=2|No change
+|}
-=Pinout=
+Verilog from [[User:Kyuusaku]]:
+<pre>{A23Z,A22Z} = A[23:22] ^ 2{~|{A[21:7],^A[23:22],VEC}}</pre>
-[[File:Neo-e0_pinout.png]]
+=Pinouts=
+==Input to output map==
+* 64 -> 5
+* 1 -> 6
+* 2 -> 7
+* 3 -> 8
+* 4 -> 9
+* 15 -> 11
+* 16 -> 12
+* 17 -> 13
+* 18 -> 14
+* 19 -> 22
+* 20 -> 23
+* 21 -> 24
+* 31 -> 27
+* 32 -> 28
+* 33 -> 29
+* 34 -> 30
+* 36 -> 39
+* 37 -> 40
+* 38 -> 41
+* 48 -> 43
+* 49 -> 44
+* 50 -> 45
+* 51 -> 46
+* 52 -> 47
+* 53 -> 55 if VEC is high
+* 54 -> 56 if VEC is high
+==Console==
+On the AES, the AND gate is used to make /SROMOE from (/SROMOEL AND /SROMOEU).
+==MV2B & MV2-01 @ H7 pinout==
+* 55 = sPCK1B
+* 56 = sPCK2B
+[[P_bus]] buffer
+==MV2B @ G2 pinout==
+{|
+|
+[[File:Neo-e0_G2_pinout.png|512px]]
+OpenOffice Draw file: [[File:Neo-e0_mv2b_G2.odg]]
+|
+*A1~A23: [[68k]] address bus
+*MCA0~MCA23: [[memory card]] address bus
+*BNK0~BNK2: memory card banking from [[NEO-D0]]
+*VEC: [[System ROM]] vector table swapping enable
+|}
+==MV2B @ F7 pinout==
+{|
+|
+[[File:Neo-e0_F7_pinout.png|512px]]
+OpenOffice Draw file: [[File:Neo-e0_mv2b_F7.odg]]
+|
+Acts just as a buffer.
+*s*: signals to both slots
+|}
+==MV2F @ E1 pinout (to be confirmed) and AES==
+{|
+|
+[[File:Neo-e0_pinout.png|512px]]
+OpenOffice Draw file: [[File:neo-e0.odg]]
+|
 *A1~A23: 68k address bus
 *Y0~Y23: memory card address bus
-*BNK0~BNK2: comes from [[NEO-D0]], ?
+*BNK0~BNK2: comes from [[NEO-D0]], [[memory card]] bank
-*VEC: BIOS vector table swapping enable
+*VEC: System ROM vector table swapping
-*ANI0, ANI1, AND0: AND gate used to generate ROMOE from ROMOEU and ROMOEL
+*ANI0, ANI1, AND0: AND gate used to generate ROMOE from (ROMOEU and ROMOEL)
+|}
 [[Category:Chips]]

NEO-E0: Difference between revisions