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3 mod: mode pins, 4 mode vector, 5 reset vector – FUJITSU MB91460 SERIES FR60 User Manual

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Chapter 9 Reset

4.Registers

4.3 MOD: Mode Pins

These pins specify the location of the mode vector and reset vector that are read after the MCU is
reset.

4.4 Mode Vector

The data written to the mode register (MODR) by the mode vector fetch operation is called the
mode data. (The mode register is an internal register and cannot be written to or read from
directly.)

After the mode register is set, the MCU operates in accordance with the modes (bus mode and
access mode) set in this register.

The mode data is set by all types of reset. Setting the mode data from the user program is not
possible.

• Mode Vector: Address 000FFF8h (Access: Byte, Half-word, Word)

• Bit32-27: Reserved bits

Always set these bits to “00000”.

If a value other than “00000” is set, the operation of the MCU is not guaranteed.

• Bit26: Internal ROM enable

Specifies whether to enable the internal ROM area.

Always set to “1”.

• Bit25-24: Bus width setting

This sets the bus width for external bus mode.

• Bit23-0: Undefined bits

4.5 Reset Vector

The MCU starts program execution from the address specified by the mode vector.

Mode pins

Mode name

Reset vector

Access area

Remarks

MD2 MD1

MD0

0

0

0

Internal ROM mode

vector

Internal

0

0

1

External ROM mode

vector

External

ROMA

Function

Remarks

0

External ROM mode

Enables the external ROM area.

1

Internal ROM mode

Enables the internal ROM area.

WTH1

WTH0

Function

Remarks

0

0

8-bit bus width

0

1

16-bit bus width

1

0

32-bit bus width

1

1

Single chip mode

31

30

29

28

27

26

25

24

Bit

0

0

0

0

0

ROMA

WTH1

WTH0

Operation mode setting bits