UPD78F9418AGK-9EU Renesas Electronics America, UPD78F9418AGK-9EU Datasheet - Page 67

• Manufacturer Part Number: UPD78F9418AGK-9EU
• Manufacturer: Renesas Electronics America

Specifications of UPD78F9418AGK-9EU

• Lead Free Status / Rohs Status: Supplier Unconfirmed

3.4.2 Short direct addressing
[Function]
[Operand format]
[Description example]
[Illustration]
The memory to be manipulated in the fixed space is directly addressed with 8-bit data in an instruction word.
The fixed space is the 256-byte space FE20H to FF1FH where the addressing is applied. An internal high-
speed RAM and special function registers (SFR) are mapped at FE20H to FEFFH and FF00H to FF1FH,
respectively.
The SFR area (FF00H to FF1FH) where short direct addressing is applied is a part of the whole SFR area.
Ports that are frequently accessed in a program and a compare register of the timer/event counter are mapped
in this area, and these SFRs can be manipulated with a small number of bytes and clocks.
When 8-bit immediate data is at 20H to FFH, bit 8 of an effective address is set to 0. When it is at 00H to 1FH,
bit 8 is set to 1. See [Illustration] below.
MOV FE30H, #50H; When setting saddr to FE30H and the immediate data to 50H
Effective
address
Identifier
saddrp
saddr
15
When 8-bit immediate data is 20H to FFH,
When 8-bit immediate data is 00H to 1FH,
7
1
Label or FE20H to FF1FH immediate data
Label or FE20H to FF1FH immediate data (even address only)
1
1
saddr-offset
Instruction code
Opcode
1
1
1
CHAPTER 3 CPU ARCHITECTURE
1
User’s Manual U13952EJ3V1UD
1
0
0
0
8
1
0
1
Description
1
1
0
1
1
1
= 1.
= 0.
0
0
0
1
0
0
0
0
0
1
0
0
Opcode
30H (saddr-offset)
50H (Immediate data)
0
Short direct memory
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