FUJITSU MB91460 SERIES FR60 - Manual (Page 1012)

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Chapter 54 Flash Memory
4.Registers
4. Registers
For the description of the Flash related registers, refer to Chapter 11 Memory Controller (Page No.167) .
5. Access Modes
This section describes the Flash memory access modes.
5.1 Access from the FR-CPU
The following three types of access mode are available:
■
64-bit CPU mode (read/execute), not for all devices
This mode does not allow data erase/write. Data can only be accessed by the CPU in lengths of words (32
bits) but is actually read from the Flash Memory in lengths of d-words (64 bits).
Programs can be executed in Flash memory while this mode is enabled.
• Specifying the mode
Use the Flash setting procedure located in the Boot-ROM at address 0000:BF60
H
with R4 (2 bits) set to 1X
B
to set this
mode. Refer to Chapter 53 Fixed Mode-Reset Vector / BOOT-ROM (Page No.983) .
• Description of operation
When reading or executing code from the Flash memory area, data is read by the CPU in word (32-bit) length units but
is actually read from memory in d-word (64-bit) length units.
Running Auto Algorithms is not possible.
■
32-bit CPU mode (read/write/execute), write not for all devices
This mode allows data erase/write. Data can only be accessed in lengths of words (32 bits).
Programs cannot be executed in Flash memory while the Flash is being written/erased.
• Specifying the mode
Use the Flash setting procedure located in the Boot-ROM at address 0000:BF60
H
with R4 (2 bits) set to 00
B
to set this
mode. Refer to Chapter 53 Fixed Mode-Reset Vector / BOOT-ROM (Page No.983) .
Flash memory always goes to 32-bit mode after a reset is cleared, when the CPU is running.
• Description of operation
When reading or executing code from the Flash memory area, data is read from memory in word (32-bit) length units.
Auto Algorithms can be run by writing commands to Flash memory. It is possible to erase/write to Flash memory by
running an Auto Algorithm. See “
7. Auto Algorithms (Page No.999) ” for details about Auto Algorithms.
■
16-bit CPU mode (read/write)
This mode allows data erase/write. Data can only be accessed in lengths of half-words (16 bits).
Programs cannot be executed in Flash memory while this mode is enabled.
• Specifying the mode
Use the Flash setting procedure located in the Boot-ROM at address 0000:BF60
H
with R4 (2 bits) set to 01
B
to set this
mode. Refer to Chapter 53 Fixed Mode-Reset Vector / BOOT-ROM (Page No.983) .
• Description of operation
When reading from the Flash memory area, data is read from memory in half-word (16-bit) length units.
Auto Algorithms can be run by writing commands to Flash memory. It is possible to erase/write the Flash memory by
running an Auto Algorithm. See “
7. Auto Algorithms (Page No.999) ” for details about Auto Algorithms.