| Bank Register Load
Instructions |
Mnemonic
|
Operation |
Address Mode |
Op-Code
(hex) |
Bytes
/Cycles |
Substituted
op-code |
Notes |
| LDK1 |
Load K1 |
Immediate |
42 |
2 / 2 |
- |
|
|
|
Zero-page,X |
54 |
2 / 4 |
- |
|
|
|
Absolute |
DC |
3 / 4 |
- |
|
LDK2
|
Load K2 |
Immediate |
C2 |
2 / 2 |
- |
|
|
|
Zero-page |
44 |
2 / 3 |
- |
|
|
|
Zero-page,X |
D4 |
2 / 4 |
- |
|
|
|
Absolute |
0B |
3 / 4 |
DC |
|
| LDK3 |
Load K3 |
Immediate |
E2 |
2 / 2 |
- |
|
|
|
Zero-page,X |
F4 |
2 / 4 |
- |
|
|
|
Absolute |
FC |
3 / 4 |
- |
|
| Prefix Instructions |
| Mnemonic |
Operation |
Address Mode |
Op-Code
(hex) |
Bytes
/Cycles |
Substituted
op-code |
Notes |
| K1_ |
K1 prefix |
Implied |
83 |
1 / 1 |
03 |
|
| K2_ |
K2 prefix |
Implied |
C3 |
1 / 1 |
03 |
|
| K3_ |
K3 prefix |
Implied |
43 |
1 / 1 |
03 |
|
| "2 in1" Instructions (standard
op with implicit prefix) |
| Mnemonic |
Operation |
Address Mode |
Op-Code
(hex) |
Bytes
/Cycles |
Substituted
op-code |
Notes |
| LDA_K2 |
LDA using K2 |
(X,ind) |
F3 |
2 / 6 |
A1 |
|
|
|
(ind),Y |
E3 |
2 / 5 |
B1 |
|
|
|
Absolute |
D3 |
3 / 4 |
AD |
|
| STA_K1 |
STA using K1 |
(X,ind) |
B3 |
2 / 6 |
81 |
|
|
|
(ind),Y |
A3 |
2 / 6 |
91 |
|
|
|
Absolute |
93 |
3 / 4 |
8D |
|
| Jump and Return
Instructions |
| Mnemonic |
Operation |
Address Mode |
Op-Code
(hex) |
Bytes
/Cycles |
Substituted
op-code |
Notes |
| JMP_K3 |
JMP using K3 |
Absolute |
13 |
3 / 3 |
4C |
1 |
| JSR_K3 |
JSR using K3 |
Absolute |
23 |
3 / 6 |
20 |
1 |
| RTS_K3 |
RTS using K3 |
Stack |
EB |
1 / 6 |
60 |
1 |
| RTI_K3 |
RTI using K3 |
Stack |
FB |
1 / 6 |
40 |
2 |
| Push and Pull Instructions |
| Mnemonic |
Operation |
Address Mode |
Op-Code
(hex) |
Bytes
/Cycles |
Substituted
op-code |
Notes |
| PHK0 |
Push K0 |
Stack |
4B |
1 / 3 |
08 |
|
| PHK1 |
Push K1 |
Stack |
6B |
1 / 3 |
08 |
|
| PHK2 |
Push K2 |
Stack |
7B |
1 / 3 |
08 |
|
| PHK3 |
Push K3 |
Stack |
5B |
1 / 3 |
08 |
|
| PLYK1 |
Pull Y, copying
the value to K1 |
Stack |
63 |
1 / 4 |
7A |
3 |
| PLYK2 |
Pull Y, copying
the value to K2 |
Stack |
73 |
1 / 4 |
7A |
3 |
| PLYK3 |
Pull Y, copying
the value to K3 |
Stack |
53 |
1 / 4 |
7A |
3 |
PLYIPL
|
Pull Y, copying
value to IP lowbyte |
Stack |
1B |
1 / 4 |
7A |
3 |
| PLYIPH |
Pull Y, copying
value to IP highbyte |
Stack |
2B |
1 / 4 |
7A |
3 |
| Miscellaneous Instructions |
| Mnemonic |
Operation |
Address Mode |
Op-Code
(hex) |
Bytes
/Cycles |
Substituted
op-code |
Notes |
NEXT
|
"Next." Jump (( IP
)) and
post-increment IP by 2 |
(( IP++ )) |
3B |
1 / 9 |
4C |
5 |
LDAW
|
LDA and copy
pointer to W |
(X,ind) |
CB |
2 / 6 |
A1 |
8 |
STAW
|
STA and copy
pointer to W |
(X,ind) |
DB |
2 / 6 |
81 |
8 |
| TSB_K1 |
TSB using K1 |
Absolute |
8B |
3 / 6 |
0C |
|
| |
|
( IP ) |
AB |
3 / 6 |
0C |
4 |
| TRB_K1 |
TRB using K1 |
Absolute |
9B |
3 / 6 |
1C |
|
| |
|
( IP ) |
BB |
3 / 6 |
1C |
4 |
SCAN_K3
|
Far Scan using K3.
(Reads bytes
for video horizontal scan line.) |
Absolute |
33 |
3 / * |
20 |
6
|
NOP1
|
One-cycle NOP |
Implied |
03 |
2 / 2 |
03 |
9 |
| K0<>K3 |
Exchange K0 and K3 |
Implied |
5C |
3 / 8 |
- |
10 |
SINC
|
Single increment
of IP |
Implied |
02 |
2 / 2 |
- |
7 |
DINC
|
Double increment
of IP |
Implied |
22 |
2 / 2 |
- |
7 |
Note 1:
K0 is
exchanged with K3.
Note 2:
K3_RTI
is only useful as a form of jump, for a debugger perhaps. The KK
typically did not use hardware interrupts because certain KK
instructions
can crash if interrupted. Circuitry to remedy this remains incomplete.
Note 3:
KK pull instructions send PLY to the
CPU. Pull
instructions cannot be created using NOPs due to the need to
increment SP. The Y in the mnemonics for KK pull
instructions
reminds the
programmer of this
compromise solution.
Note 4:
I think
I intended these for manipulation of pixel bit-maps,
with IP providing accelerated addressing through the array.
I don't recall whether the capability ever got used.
Note 5:
NEXT is
discussed on this
page
Note 6:
The K3_SCAN
instruction is discussed here.
Note 7:
SINC and
DINC are discussed here.
Note 8:
these
instructions are used to provide X-Indirect-Y Addressing,
explained here.
Note 9:
1CYNOP
(1-cycle NOP) is intended for software timing loops
Note 10: K0<>K3
is used during initialization, before the 16MB
map is enabled, as a means to load K0. Otherwise it is suicidal to
load
K0 but not the PC.
|
