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JRE cc,label     Jump Relative     Rabbit 4000 Instruction
Opcode
Instruction
Clocks
Operation

----

JRE cc,label
JRE cc,mn1
9 (2,2,2,2,1)
 if {cc} PC = PC2 + ee

ED C3 ee low eehigh

JRE NZ,mn

9 (2,2,2,2,1)

if {NZ} PC = PC + ee

ED CB ee low eehigh

JRE Z,mn

9 (2,2,2,2,1)

if {Z} PC = PC + ee

ED D3 ee low eehigh

JRE NC,mn

9 (2,2,2,2,1)

if {NC} PC = PC + ee

ED DB ee low eehigh

JRE C,mn

9 (2,2,2,2,1)

if {C} PC = PC + ee


1 The 16-bit constant mn is the destination logical address of the jump. 2 The value of PC after the instruction fetch.
Flags ALTD IOI/IOE
S
Z
L/V
C
F
R
SP
S
D
-
-
-
-

Description

If condition "cc" is true, this instruction transfers control to the specifed address. The address is specified by a label or logical address. The assembler translates the label or logical address "mn" to a 16-bit signed displacement value, "ee".

The displacement value "ee" is relative to the address of the first byte of the instruction following JRE. This fact is because the processor calculates the new PC value after it increments the PC for the instruction fetch of JRE.

If condition "cc" is not true, PC is incremented normally.

Condition Code
Flag Bit Value
Description

NZ

Z=0

True when the Z flag has not been set

Z

Z=1

True when the Z flag has been set

NC

C=0

True when the C flag has not been set

C

C=1

True when the C flag has been set


Note that the relative jump has a range of [-32768, 32767] from the address of the first byte of the instruction following the JRE instruction.

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