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