expression     → term
term           → factor ( ( "-" | "+" ) factor )*
factor         → unary ( ( "/" | "*" | "%" ) unary )*
unary          → ( "~" | "+" | "-" ) unary
               | shift
shift          → andl ( ( "<<" | ">>" ) andl )*
andl           → orl ( "&" orl )*
orl            → andl ( ( "|" | "^" ) andl )*
primary        → number
               | "(" expression ")"

number → "%" base2-number
       | "$" base16-number
       | "0b" base2-number
       | "0x" base16-number
       | base10-number

imm → ("#")? expression
uimm8  → imm
uimm19 → imm
uimm25 → imm

alu → and | or | xor | add | sub | ad2 | sr | rr | sl | rl | rl8

xy_src → "mc0" | "mc1" | "mc2" | "mc3"
       | "m0"  | "m1"  | "m2"  | "m3"

mov_ram_x → "mov" xy_src  "," "x"
mov_mul_p → "mov" "mul"   "," "p"
mov_ram_p → "mov" xy_src  "," "p"

x_bus → mov_ram_x | mov_mul_p | mov_ram_p

mov_ram_y → "mov" xy_src  "," "y"
clr_a     → "clr" "a"
mov_alu_a → "mov" "alu"    "," "a"
mov_ram_a → "mov" xy_src  "," "a"

y_bus → mov_ram_y | clr_a | mpv_alu_a | mov_ram_a

d1_dest → "rx"  | "pl"
        | "ra0" | "wa0"
        | "lop" | "top"
        | "ct0" | "ct1" | "ct2" | "ct3"

d1_src → "mc0" | "mc1" | "mc2" | "mc3"
       | "m0"  | "m1"  | "m2"  | "m3"
       | "alh" | "all"

mov_imm_d1 → "mov" uimm8  "," d1_dest
mov_ram_d1 → "mov" d1_src "," d1_dest

d1_bus → mov_imm_d1 → mov_ram_d1

nop → "nop"

op → ( nop | alu | x_bus | y_bus | d1_bus ) +

load_dest → "mc0" | "mc1" | "mc2" | "mc3"
          | "rx"  | "pl"
          | "ra0" | "wa0"
          | "lop" | "pc"

load_cond → "z"  | "nz"
          | "s"  | "ns"
          | "c"  | "nc"
          | "t0" | "nt0"
          | "zs" | "nzs"

mvi      → "mvi" uimm25 load_dest
mvi_cond → "mvi" uimm19 load_dest load_cond

load → mvi | mvi_cond

dma_ingress → "m0" | "m1" | "m2" | "m3"
            | "prg"

dma_egress  → "m0" | "m1" | "m2" | "m3"

add_mode = "0" | "1" | "2" | "4" | "8" | "16" | "32" | "64"

dma_dmah → ("dma" | "dmah") add_mode?

dma_length_ram → "m0"  | "m1"  | "m2"  | "m3"
               | "mc0" | "mc1" | "mc2" | "mc3"

dma_ingress_imm → dma_dmah "d0"       "," dma_ingress "," uimm8
dma_egress_imm  → dma_dmah dma_egress "," "d0"        "," uimm8
dma_ingress_ram → dma_dmah "d0"       "," dma_ingress "," dma_length_ram
dma_egress_ram  → dma_dmah dma_egress "," "d0"        "," dma_length_ram

dma → dma_ingress_imm | dma_egress_imm | dma_ingress_ram | dma_egress_ram

jump_cond → "z"  | "nz"
          | "s"  | "ns"
          | "c"  | "nc"
          | "t0" | "nt0"
          | "zs" | "nzs"

jmp      → "jmp" uimm8
jmp_cond → "jmp" jump_cond

jump → jmp | jmp_cond

loop → "btm" | "lps"

end → "end" | "endi"

instruction → op
	    | load
	    | dma
	    | jump
	    | loop
	    | end

assignment_statement → identifier "=" expression "\n"

label → identifier ":"

instruction_statement → label? instruction? "\n"

statement → assignment_statement
          | instruction_statement