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R8C/20 Group, R8C/21 Group 3. Memory

Rev.2.00 Aug 27, 2008 Page 13 of 458

REJ09B0250-0200

3. Memory

3.1 R8C/20 Group

Figure 3.1 shows a Memory Map of R8C/20 Group. The R8C/20 Group has 1 Mbyte of address space from

address 00000h to FFFFFh.

The internal ROM is allocated lower addresses, beginning with address 0FFFFh. For example, a 48-Kbyte internal

ROM is allocated addresses 04000h to 0FFFFh.

The fixed interrupt vector table is allocated addresses 0FFDCh to 0FFFFh. They store the starting address of each

interrupt routine.

The internal RAM is allocated higher addresses, beginning with address 00400h. For example, a 2.5-Kbyte

internal RAM is allocated addresses 00400h to 00DFFh. The internal RAM is used not only for storing data but

also for calling subroutines and as stacks when interrupt requests are acknowledged.

Special function registers (SFR) are allocated addresses 00000h to 002FFh. The peripheral function control

registers are allocated here. All addresses within the SFR, which have nothing allocated are reserved for future

user and cannot be accessed by users.

Figure 3.1 Memory Map of R8C/20 Group

Undefined instruction

Overflow

BRK instruction

Address match

Single step

Watchdog timer•oscillation stop detection•voltage detection

Address break

(Reserved)

Reset

FFFFFh

0FFFFh

0YYYYh

0XXXXh

00400h

002FFh

00000h

Internal ROM

(program ROM)

Internal RAM

SFR

(Refer to 4. Special

Function Registers

(SFRs))

0FFFFh

0FFDCh

NOTES:

1. The blank regions are reserved. Do not access locations in these regions.

2. Do not use addresses 20000h to 23FFFh because these areas are used for the emulator debugger. Refer to 23. Notes on

Emulator Debugger.

Reserved area

01300h

02000h

Internal ROM

(2)

(program ROM)

Part Number

Internal ROM

Size Address 0YYYYh Address ZZZZZh

R5F21206JFP, R5F21206KFP

R5F21207JFP, R5F21207KFP

R5F21208JFP, R5F21208KFP

R5F2120AJFP, R5F2120AKFP

R5F2120CJFP, R5F2120CKFP

32 Kbytes

48 Kbytes

64 Kbytes

96 Kbytes

128 Kbytes

08000h

04000h

13FFFh

1BFFFh

23FFFh

Internal RAM

Address 0XXXXh

00BFFh

00DFFh

00FFFh

2 Kbytes

2.5 Kbytes

3 Kbytes

5 Kbytes

6 Kbytes

Size

ZZZZZh

Internal RAM

03000h

0SSSSh

Address 0SSSSh

037FFh

03BFFh

Brand	Renesas
Model	R8C/20
Category	Control Unit
Language	English

Renesas R8C/20 User Manual

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Renesas R8C/20 Specifications

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