PM0044 Datasheet, PDF (113/162 Pages) STMicroelectronics – STM8 CPU programming manual

PM0044
STM8 instruction set
JRxx
Conditional Jump
Relative Instruction
JRxx
Syntax
JRxx dst
e.g. JRxx loop
Operation
PC = PC+lgth
PC <= PC + dst, if Condition is True
Description
Conditional relative jump. PC is updated by the signed addition of PC and
dst, if the condition is true. Control, then passes to the statement
addressed by the program counter. Else, the program continues normally.
Instruction overview
mnem
JRxx
Instruction List
dst
Mem
Affected condition flags
V
I1
H
I0
N
Z
C
-
-
-
-
-
-
-
mnem
JRC
JREQ
JRF
JRH
JRIH
JRIL
JRM
JRMI
JRNC
JRNE
JRNH
JRNM
JRNV
JRPL
JRSGE
JRSGT
JRSLE
JRSLT
JRT
JRUGE
JRUGT
JRULE
JRC
JRULT
JRV
meaning
Carry
Equal
False
Half-Carry
Interrupt Line is High
Interrupt Line is Low
Interrupt Mask
Minus
Not Carry
Not Equal
Not Half-Carry
Not Interrupt Mask
Not Overflow
Plus
Signed Greater or Equal
Signed Greater Than
Signed Lower or Equal
Signed Lower Than
True
Unsigned Greater or Equal
Unsigned Greater Than
Unsigned Lower or Equal
Carry
Unsigned Lower Than
Overflow
sym
=
Condition
C=1
Z=1
False
H=1
<0
<> 0
>= 0
>=
>
<=
<
>
<=
I=1
N=1
C=0
Z=0
H=0
I=0
V=0
N=0
(N XOR V) = 0
(Z OR (N XOR V)) = 0
(Z OR (N XOR V)) = 1
(N XOR V) = 1
True
C=0
C = 0 and Z = 0
C = 1 or Z = 1
C=1
C=1
V=1
Op-code (OC)
25
27
21
90
29
90
2F
90
2E
90
2D
2B
24
26
90
28
90
2C
28
2A
2E
2C
2D
2F
20
24
22
23
25
25
29
Detailed description
dst
Asm
cy lgth
Op-code(s)
ST7
shortoff
JRxx $15
1/2 2
Op-code XX
✗
shortoff
JRxx $15
1/2 3
90 Op-code XX
✗
Doc ID 13590 Rev 3
113/162