LMIA advanced development kit
This project was developed as a simple development kit for programming and microprogramming the LMIA system.
μASM instruction set
NOP
No-operation. This wastes one clock cycle
MOV [regA] [regB]
Move value in regA to regB
This operation uses the bus
If regB is LC, no other LC operation can be specified in the same cycle
MVN {[reg] | [const]}
Move the inverse of a value (from register or constant) into register AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
MVZ
Set AR to zero.
Sets flags: Z, N
ADD {[reg] | [const]}
Add value (from register or constant) to register AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, O, C
SUB {[reg] | [const]}
Subtract value (from register or constant) from register AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, O, C
AND {[reg] | [const]}
Perform bitwise AND with given value (from register or constant) and register AR. reg is ignored and only prevalent due to a microcompiler quirk; expect it to be removed in future releases.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N
ORR {[reg] | [const]}
Perform bitwise Or with given value (from register or constant) and register AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N
ADN {[reg] | [const]}
Add value (from register or constant) to register AR without updating flags.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
LSL
Performs a logical shift left of AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
BSL
Performs a logical shift left of AR and HR as if they were one 32-bit register where AR corresponds to the most-significant bits.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
ASR
Performs an arithmetic shift right on AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
BSR
Performs an arithmetic shift right of AR and HR as if they were one 32-bit register where AR corresponds to the most-significant bits.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
LSR
Performs a logical shift right of AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
ROL
Performs an arithmetic rotate right on AR.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
BRL
Performs an arithmetic shift left of AR and HR as if they were one 32-bit register where AR corresponds to the most-significant bits.
This operation uses the bus
If a constant is passed, this operation cannot be parallellized
Sets flags: Z, N, C
LCSET [const]
Set LC to value of constant.
CONST [const]
Set AR to value of cosntant.
This operation cannot be parallelized
INCPC
Increment value in PC by one.
DECLC
Decrement value in LC by one.
CALL [label]
Move value in uPC to uSP (MySPC) and set value in uPC to point to the address of the given label.
RET
Move value in uSP (MySPC) into uPC.
HALT
Stop execution and set value int uPC to 0.
BRA [label]
Perform an unconditional branch to the address of the given label.
BNZ [label]
Branch to address of label if Z-flag is 0.
BRZ [label]
Branch to address of label if Z-flag is 1.
BRN [label]
Branch to address of label if N-flag is 1.
BRC [label]
Branch to address of label if C-flag is 1.
BRO [label]
Branch to address of label if O-flag is 1.
BLS [label]
Branch to address of label if L-flag is 1.
BNC [label]
Branch to address of label if C-flag is 0.
BNO [label]
Branch to address of label if O-flag is 0.
Compiler/weaver directives
#define [name] [const]
Define a compile-time constant. This will replace all (valid) constant declarations with the given name with the value supplied here.
NOTE: Constant names are case-insensitive; i.e. FOO and foo are functionally indistinguishable to the compiler.
#data [address] [const]
Define an initial value in the program memory at the given address.
$[label]
Define a compile-time label at the given position in the microprogram. Labels can be referenced using an '@' symbol.
For example: $BAR would declare a label BAR which can be referenced with @BAR.
NOTE: Label names are case-insensitive; i.e. @FOO and @foo are functionally indistinguishable to the compiler.
Flags
Flags - aside from L - are set based on ALU operations, so they depend on AR and the BUS. Henceforth, unless otherwise implied or stated, AR will refer to the state/value of AR after an ALU operation.
Z
Set if AR == BUS
N
Set if sign bit in AR is set.
O
Set if sign of AR differs from signs of both AR and BUS before the arithmetic operation.
C
Set if AR is less than or equal to AR before the arithmetic operation.
L
Set if LC == 0.