FR65E Fujitsu Microelectronics, Inc., FR65E Datasheet - Page 27

• Manufacturer Part Number: FR65E
• Description: 32-bit Microcontroller
• Manufacturer: Fujitsu Microelectronics, Inc.

Precautions for use of this model
Use of Built-in RAM
After mode register setting the vector area is an internal area. Therefore before writing to the mode register
it is necessary to rewrite the TBR register so that the vector area is changed to an external area.
The MB91307B provides 128 KB of built-in RAM. To enable use of this RAM, the mode register must be set to
internal ROM external bus mode (ROMA=1).
• The reset vector is fixed at 000F_FFFC
• For the MB91307B, the 128Kbyte RAM area is from 0004_0000
• In order to use RAM the mode register must be set to internal ROM external bus mode.
• In internal ROM external bus mode the built-in RAM area can be used, but the vector area 000F_FFXX
• When placing instruction code in RAM, nothing should be placed in the last 8 bytes of the area 0005_FFFF8h
to 000F_FFFF
internal area and cannot be accessed externally. Please refer to the following explanation.
to 0005_FFFF
H
H
. (This is an instruction code prohibited area.)
is access prohibited.
FFFF FFFF
0000 0000
0000 0400
0001 0000
0004 0000
0006 0000
0010 0000
H
H
H
H
H
H
H
After reset release
External area
External area
External area
prohibited
Access
I/O
I/O
H
The shaded sections indicate internal areas
.
Refer to I/O map
Direct addressing
area
H
to 0005_FFFF
Internal ROM external bus mode
After mode setting
External area
Internal RAM
prohibited
prohibited
Access
Access
128 KB
I/O
I/O
H
. The area from 0006_0000
MB91307B
H
is an
H
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