11.2. Instrukční sada procesoru F21
FIXME:
Tabulka 11.2. F21 Instruction Set
| opcode | name | description | forth |
|---|
| 00 | else | unconditional jump | ELSE |
| 01 | T=0 | jump if T0-19 zero | DUP IF |
| 02 | call | push P+1 to R, jump | : |
| 03 | C=0 | jump if T20 zero | CARRY? IF |
| 04 | | | |
| 05 | | | |
| 06 | ret | pop P from R | ; |
| 07 | | | |
| 08 | @R+ | fetch, address in R, increment R | R@ @ R> 1+ >R |
| 09 | @A+. | fetch, address in A, increment A | A @ @ 1 A +! |
| 0A | # | fetch 20-bit in-line literal | LIT |
| 0B | @A | fetch, address in A | A @ @ |
| 0C | !R+ | store, address in R, increment R | R@ ! R> 1+ >R |
| 0D | !A+ | store, address in A, increment A | A @ ! 1 A +! |
| 0E | | | |
| 0F | !A | store, address in A | A @ ! |
| 10 | com | complement T | -1 XOR |
| 11 | 2* | shift T, 0 to T0 | 2* |
| 12 | 2/ | shift T, T20 to T19 | 2/ |
| 13 | +* | add S to T if T0 one | DUP 1 AND IF OVER + THEN |
| 14 | -or | exclusive-or S to T | XOR |
| 15 | and | and S to T | AND |
| 16 | | | |
| 17 | + | add S to T | + |
| 18 | pop | pop R, push into T | R> |
| 19 | A@ | push A into T | A @ |
| 1A | dup | push T into T | DUP |
| 1B | over | push S into T | OVER |
| 1C | push | pop T, push into R | >R |
| 1D | A! | pop T into A | A ! |
| 1E | nop | | NOP |
| 1F | drop | pop T | DROP |
Implementace slov FORTHu jako maker:
: @ A! @A ;
: ! A! !A ;
: -1 dup dup -or com ;
: 0 dup dup -or ;
: OR over com and -or ;
: SWAP A! push A@ pop ;
: long_jump # (com) push ;
