Z8F6421PM020SC Datasheet, PDF (257/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
237
Condition Codes
The C, Z, S and V flags control the operation of the conditional jump (JP cc and JR cc)
instructions. Sixteen frequently useful functions of the flag settings are encoded in a 4-bit
field called the condition code (cc), which forms Bits 7:4 of the conditional jump instruc-
tions. The condition codes are summarized in Table 123. Some binary condition codes can
be created using more than one assembly code mnemonic. The result of the flag test oper-
ation decides if the conditional jump is executed.
Table 123. Condition Codes
Binary
0000
0001
0010
0011
0100
0101
0110
0110
0111
0111
1000
1001
1010
1011
1100
1101
1110
1110
1111
1111
Assembly
Hex Mnemonic Definition
Flag Test Operation
0F
Always False
–
1 LT
Less Than
(S XOR V) = 1
2 LE
Less Than or Equal
(Z OR (S XOR V)) = 1
3 ULE
Unsigned Less Than or Equal (C OR Z) = 1
4 OV
Overflow
V=1
5 Ml
Minus
S=1
6Z
Zero
Z=1
6 EQ
Equal
Z=1
7C
Carry
C=1
7 ULT
Unsigned Less Than
C=1
8 T (or blank) Always True
–
9 GE
Greater Than or Equal
(S XOR V) = 0
A GT
Greater Than
(Z OR (S XOR V)) = 0
B UGT
Unsigned Greater Than
(C = 0 AND Z = 0) = 1
C NOV
No Overflow
V=0
D PL
Plus
S=0
E NZ
Non-Zero
Z=0
E NE
Not Equal
Z=0
F NC
No Carry
C=0
F UGE
Unsigned Greater Than or Equal C = 0
PS019915-1005
eZ8 CPU Instruction Set