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

Rev.2.00 Aug 27, 2008 Page 14 of 458

REJ09B0250-0200

3.2 R8C/21 Group

Figure 3.2 shows a Memory Map of R8C/21 Group. The R8C/21 Group has 1 Mbyte of address space from

address 00000h to FFFFFh.

The internal ROM (program 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 ROM (data flash) is allocated addresses 02400h to 02BFFh.

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

use and cannot be accessed by users.

Figure 3.2 Memory Map of R8C/21 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

02BFFh

02400h

Internal ROM

(data flash)

(1)

Reserved area

01300h

02000h

Internal ROM

(3)

(program ROM)

ZZZZZh

NOTES:

1. Data flash block A (1 Kbyte) and B (1 Kbyte) are shown.

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

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

Emulator Debugger.

Part Number

Internal ROM

Size Address 0YYYYh Address ZZZZZh

R5F21216JFP, R5F21216KFP

R5F21217JFP, R5F21217KFP

R5F21218JFP, R5F21218KFP

R5F2121AJFP, R5F2121AKFP

R5F2121CJFP, R5F2121CKFP

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

Address 0SSSSh

037FFh

03BFFh

Internal RAM

03000h

0SSSSh

Brand	Renesas
Model	R8C/20
Category	Control Unit
Language	English

Renesas R8C/20 User Manual

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