s3c72m9 Samsung Semiconductor, Inc., s3c72m9 Datasheet - Page 106

• Manufacturer Part Number: s3c72m9
• Description: The S3c72m5/s3c72m7/s3c72m9 Single-chip Cmos Microcontroller Has Been Designed For High Performance Using Samsung S
• Manufacturer: Samsung Semiconductor, Inc.

SAM47 INSTRUCTION SET
Instruction Reference Area (Concluded)
— Using the 1-byte REF instruction to execute one 2-byte or two 1-byte instructions;
— Branching to any location by referencing a branch address that is stored in the look-up table;
— Calling subroutines at any location by referencing a call address that is stored in the look-up table.
If necessary, a REF instruction can be circumvented by means of a skip operation prior to the REF in the execution
sequence. In addition, the instruction immediately following a REF can also be skipped by using an appropriate
reference instruction or instructions.
Two-byte instructions which can be referenced using a REF instruction are limited to instructions with an execution
time of two machine cycles. (An exception to this rule is XCH A,DA.) In addition, when you use REF to reference
two 1-byte instructions stored in the reference area, specific combinations must be used for the first and second 1-
byte instruction. These combinations are described in Table 5-1.
5-2
NOTE:
Instruction
If the MSB value of the first one-byte instruction is "0", the instruction cannot be
referenced by a REF instruction.
Table 5-1. Valid 1-Byte Instruction Combinations for REF Look-Ups
XCH
XCH
XCH
LD
LD
LD
LD
First 1-Byte Instruction
Operand
A,@WX
A,@WX
A,@WL
A,@WL
A,@HL
@HL,A
A,@HL
Instruction
DECS
DECS
DECS
DECS
DECS
DECS
S3C72M5/C72M7/C72M9/P72M9 (Preliminary Spec)
Second 1-Byte Instruction
INCS
INCS
INCS
INCS
INCS
INCS
INCS
INCS
Operand
WX
HL
W
W
W
W
H
H
L
L
X
X
L
L