External Bus Interface (Extbus) - Fujitsu FR Series Application Note

2.8 External Bus Interface (EXTBUS)

If the external bus interface is used, it has to be configured properly. Please refer to the
hardware manual and the data sheet for detailed information. The startup file supports the
configuration of the external bus interface.
Available settings for EXTBUS:
- ON
- OFF
- DEFAULT
Note: Not all devices support an external bus interface. The following devices do not offer
an external bus interface: MB91464A, MB91467C, MB91465K, MB91463N,
MB91465X.
Note: Be aware, that the device might startup in external bus mode by default after reset.
Example:
The external bus interface should be configured.
#set EXTBUS
The startup file supports the configuration of the following registers, too.
- CSER Chip Select Enable Register
- ASR0-7 Area Select Registers 0-7
- ACR0-7 Area Configuration Registers 0-7
- AWR0-7 Area Wait Registers 0-7
- MCRA
MEMORY SETTING REGISTER for extend type - A for SDRAM/FCRAM auto
Refresh control register
- RCR
- TCR Pin/Timing Control Register
- CHER Cache Enable Register
- PFR0 – 10 Port Function Register 0-7
© Fujitsu Microelectronics Europe GmbH
Start91460.asm
Chapter 2 Settings of the Start91460.asm
The ext. bus interface is enabled and will be configured.
The ext. bus interface is disabled. The port function registers are set
to general I/O. The registers of external bus interface will not be
touched by the startup file.
Neither the register nor the respective port function registers are
touched by the startup file.
ON ; <<< Ext. Bus on/off
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