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Registers, Access modes, 1 access from the fr-cpu – FUJITSU MB91460 SERIES FR60 User Manual

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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.