$Header: /home/radek/cvs/forth-book/db-mc68k-inst/Bcc,v 1.5 2003/12/28 18:21:56 radek Exp $
Bcc — Branch Conditionally
Program Control Operation
Bcc label
BCClabel
BCSlabel
BEQlabel
BGElabel
BGTlabel
BHIlabel
BLElabel
BLSlabel
BLTlabel
BMIlabel
BNElabel
BPLlabel
BVClabel
BVSlabel
Podle podmínky instrukce pokračuje další instrukcí, nebo vykoná skok / převede řízení programu na adresu danou aktuální adresou a uvedeným posunutím.
If Condition True PC + dn → PC
Tabulka 29. Podmínkové kódy *:[2:3:1:7]
Mnemonic | Podmínka | Kód | Test |
---|---|---|---|
T* / BRA | True | 0000 | 1 |
F* / BSR | False | 0001 | 0 |
HI | High | 0010 | (not C) and (not Z) |
LS | Low or Same | 0011 | C or Z |
CC(HI) | Carry Clear | 0100 | C |
CS(LO) | Carry Set | 0101 | C |
NE | Not Equal | 0110 | Z |
EQ | Equal | 0111 | Z |
VC | Overflow Clear | 1000 | V |
VS | Overflow Set | 1001 | V |
PL | Plus | 1010 | N |
MI | Minus | 1011 | N |
GE | Grerat or Equal | 1100 | (N and V) or ((not N) and (not V)) |
LT | Less Than | 1101 | (N and (not V)) or ((not N) and V) |
GT | Greater Than | 1110 | (N and V and (not Z)) or ((not N) and (not V) and (not Z)) |
LE | Less or Equal | 1111 | Z or N and (not V) or (not N) and V |
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 +---+---+---+---+---------------+-------------------------------+ | 0 | 1 | 1 | 0 | condition | 8-bit displacement | +---+---+---+---+---------------+-------------------------------+ | 16-bit displacement if 8-bit displacement = $00 | +---------------------------------------------------------------+ | 32-bit displacement if 8-bit displacement = $00 | +---------------------------------------------------------------+