Fujitsu MB91460 SERIES FR60 User Manual page 160

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.
Mode pins
MD2 MD1 MD0
0 0 0
0 0 1
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)
31
0
• 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.
ROMA
0
1
Always set to "1".
• Bit25-24: Bus width setting
This sets the bus width for external bus mode.
WTH1
0
0
1
1
• Bit23-0: Undefined bits
4.5 Reset Vector
The MCU starts program execution from the address specified by the mode vector.
144
Mode name
Internal ROM mode
vector
External ROM mode
vector
30 29 28
0 0 0
Function
External ROM mode
Internal ROM mode
WTH0 Function
0 8-bit bus width
1 16-bit bus width
0 32-bit bus width
1 Single chip mode
Reset vector
Access area
Internal
External
27 26 25
0 ROMA WTH1
Operation mode setting bits
Enables the external ROM area.
Enables the internal ROM area.
Remarks
24 Bit
WTH0
Remarks
Remarks