CDP1805AC, CDP1806AC
TABLE 1. INSTRUCTION SUMMARY (SEE NOTES) (Continued)
INSTRUCTION
NO. OF
MACHINE
CYCLES
MNEMONIC
OP CODE
OPERATION
DECIMAL SUBTRACT MEMORY
4
WITH BORROW, IMMEDIATE
DSBI
687F
D - M(R(P)) - (NOT DF) → DF, D
R(P) + 1 → R(P)
DECIMAL ADJUST → DF, D
BRANCH INSTRUCTIONS - SHORT BRANCH
SHORT BRANCH
2
BR
30
M(R(P)) → R(P).0
NO SHORT BRANCH (See SKP)
2
NBR
38
R(P) + 1 → R(P)
(Note 11)
SHORT BRANCH IF D = 0
2
BZ
32
IF D = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF D NOT 0
2
BNZ
3A
IF D NOT 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF DF = 1
2
BDF
33
IF DF = 1, M(R(P)) → R(P).0
(Note 11) ELSE R(P) + 1 → R(P)
SHORT BRANCH IF POS OR ZERO
2
BPZ
33
IF DF = 1, M(R(P)) → R(P).0
(Note 11) ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EQUAL OR
2
GREATER
BGE
33
IF DF = 1, M(R(P)) → R(P).0,
(Note 11) ELSE R(P) + 1 → R(P)
SHORT BRANCH IF DF = 0
2
BNF
3B
IF D = 0, M(R(P)) → R(P).0,
(Note 11) ELSE R(P) + 1 → R(P)
SHORT BRANCH IF MINUS
2
BM
3B
IF D = 0, M(R(P)) → R(P).0,
(Note 11) ELSE R(P) + 1 → R(P)
SHORT BRANCH IF LESS
2
BL
3B
IF D = 0, M(R(P)) → R(P).0,
(Note 11) ELSE R(P) + 1 → R(P)
SHORT BRANCH IF Q = 1
2
BQ
31
IF Q = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF Q = 0
2
BNQ
39
IF Q = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
SHORT BRANCH IF EF1 = 1
2
(EF1 = VSS)
SHORT BRANCH IF EF1 = 0
2
(EF1 = VDD)
SHORT BRANCH IF EF2 = 1
2
(EF2 = VSS)
SHORT BRANCH IF EF2 = 0
2
(EF2 = VDD)
SHORT BRANCH IF EF3 = 1
2
(EF3 = VSS)
SHORT BRANCH IF EF3 = 0
2
(EF3 = VDD)
SHORT BRANCH IF EF4 = 1
2
(EF4 = VSS)
SHORT BRANCH IF EF4 = 0
2
(EF4 = VDD)
SHORT BRANCH ON COUNTER
3
INTERRUPT
B1
34
IF EF1 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
BN1
3C
IF EF1 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
B2
35
IF EF2 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
BN2
3D
IF EF2 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
B3
36
IF EF3 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
BN3
3E
IF EF3 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
B4
37
IF EF4 = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
BN4
3F
IF EF4 = 0, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
BCI
683E IF CI = 1, M(R(P)) → R(P).0; 0 → CI
(Note 12) ELSE R(P) + 1 → R(P)
SHORT BRANCH ON EXTERNAL
3
INTERRUPT
BXI
683F IF XI = 1, M(R(P)) → R(P).0
ELSE R(P) + 1 → R(P)
19