996
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.
