opcode   | mnem.     | SP   | RP     | T     | N      | R      | PC     |cycles
---------|-----------|------|--------|-------|--------|--------|--------|------
0000000X | NOP       | SP   | RETURN | T     | N      | RETURN | RETURN | 1
0000001X | RSHIFT    | SP-1 | RETURN | expr. | [SP-1] | RETURN | RETURN | 1
0000010X | ADD       | SP-1 | RETURN | expr. | [SP-1] | RETURN | RETURN | 1
0000011X | SUB       | SP-1 | RETURN | expr. | [SP-1] | RETURN | RETURN | 1
00001XXX | LOGIC     | SP-1 | RETURN | expr. | [SP-1] | RETURN | RETURN | 1
0001000X | SWAP      | SP   | RETURN | N     | T      | RETURN | RETURN | 1
0001001X | DUP       | SP+1 | RETURN | T     | T      | RETURN | RETURN | 1
00010100 | OVER      | SP+1 | RP     | N     | T      | R      | PC+1   | 1
00010101 | RDUP      | SP   | RP+1   | T     | N      | R      | PC+1   | 1
00010110 | NLZ       | SP   | RP     | expr. | N      | R      | PC+1   | 1
00010111 | MULT      | SP   | RP     | expr. | expr.  | R      | PC+1   | 2
0001100X | LOAD      | SP   | RP     | expr. | N      | R      | PC+1   | 1*
0001101X | STORE     | SP-2 | RP     | expr. | [SP-2] | R      | PC+1   | 1*
00011100 | RDROP     | SP   | RP-1   | T     | N      | [RP-1] | PC+1   | 1
00011101 | POP       | SP+1 | RP-1   | R     | T      | [RP-1] | PC+1   | 1
00011110 | PUSHPC    | SP   | RP+1   | T     | N      | PC+1   | PC+1   | 1
00011111 | PUSH      | SP-1 | RP+1   | N     | [SP-1] | T      | PC+1   | 1
001XXXXX | IMMED     | SP+1 | RP     | expr. | T      | R      | PC+1   | 1
010XXXX0 | JUMP      | SP-1 | RP     | N     | [SP-1] | R      | TARGET | 1*
010XXXX1 | JUMP DROP | SP-2 | RP     | expr. | [SP-2] | R      | TARGET | 1*
011XXXX0 | CALL      | SP-1 | CALL   | N     | [SP-1] | CALL   | TARGET | 1*
011XXXX1 | CALL DROP | SP-2 | CALL   | expr. | [SP-2] | CALL   | TARGET | 1*
1XXXXXXX | MERGE     | SP   | RP     | expr. | N      | R      | PC+1   | 1

RP:RETURN = opcode[0] ? (RP-1) : RP
R:RETURN  = opcode[0] ? [RP-1] : R
PC:RETURN = opcode[0] ? R : (PC+1)
RP:CALL   = cond(N) ? (RP+1) : RP
R:CALL    = cond(N) ? (PC+1) : R
PC:TARGET = cond(N) ? (rel ? (PC+1+T) : T) : (PC+1)

(*) External device can insert additional wait states.

opcode | T:expr. | N:expr.  |
-------|---------|----------|
RSHIFT | N >> T  |   ---    |
ADD    | N + T   |   ---    |
SUB    | N - T   |   ---    |
NIP    | T       |   ---    |
AND    | N & T   |   ---    |
OR     | N | T   |   ---    |
XOR    | N ^ T   |   ---    |
NLZ    | nlz(T)  |   ---    |
MULT   | msw <- N*T -> lsw  |
LOAD   | data in |   ---    |
STORE  | [SP-1]  |   ---    |
IMMED  | immed   |   ---    |
J DROP | [SP-1]  |   ---    |
C DROP | [SP-1]  |   ---    |
MERGE  | T:merge |   ---    |