Renesas rl78 Benutzerhandbuch

RL78/G1A

CHAPTER 28 INSTRUCTION SET

R01UH0305EJ0200 Rev.2.00

832

Jul 04, 2013

28.1.3 Description of flag operation column

The change of the flag value when the instruction is executed is shown in the “Flag” column using the following

symbols.

Table 28-3. Symbols in “Flag” Column

Symbol

Change of Flag Value

(Blank)

1
×
R

Unchanged

Cleared to 0

Set to 1

Set/cleared according to the result

Previously saved value is restored

28.1.4 PREFIX instruction

Instructions with “ES:” have a PREFIX operation code as a prefix to extend the accessible data area to the 1 MB space

(00000H to FFFFFH), by adding the ES register value to the 64 KB space from F0000H to FFFFFH. When a PREFIX

operation code is attached as a prefix to the target instruction, only one instruction immediately after the PREFIX operation

code is executed as the addresses with the ES register value added.

A interrupt and DMA transfer are not acknowledged between a PREFIX instruction code and the instruction

immediately after.

Table 28-4. Use Example of PREFIX Operation Code

Opcode

Instruction

1 2 3 4 5

MOV !addr16, #byte

CFH

!addr16

#byte

−

MOV ES:!addr16, #byte

11H

CFH

!addr16

#byte

MOV A, [HL]

8BH

−

MOV A, ES:[HL]

11H

8BH

−

Caution Set the ES register value with MOV ES, A, etc., before executing the PREFIX instruction.