Fujitsu FR20 Home Theater Server User Manual


 
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CHAPTER 21 Flash Memory
21.4 Flash Memory Auto Algorithm (Embedded Algorithm
TM
)
Writing or erasing of the flash memory cell is carried out by initiating the auto algorithm
stored by the flash memory itself.
Command Operation
In order to initiate the auto algorithm, execute continuous writing of half-word (16-bit) data for 1 to 6 times
to the flash memory. This is called a command.
If an invalid address or data is written, or the address and data are written in the wrong order, the flash
memory is reset to read mode.
Table 21.4-1 lists the command.
*: Commands must be issued by writing half-words under the FR-CPU programming mode.
RA: Read address /RD: Read data
PA: Write address/PD: Write data
SA: Sector address (specification of any address in the sector. Refer to Table 21.1-1 and Table 21.1-2 )
Erase suspension command (B0
H
) and erase restart command (30
H
) are only valid while erasing the sector.
Two types of reset command can reset the flash memory to read mode.
Table 21.4-1 Command sequence table
Command
sequence
Access numbers
1 Writing Cycle 2 Writing Cycle 3 Writing Cycle 4 Writing Cycle 5 Writing Cycle 6 Writing Cycle
Address Data Address Data Address Data Address Data Address Data Address Data
Read/Reset 1
XXXXXXXX
H
F0F0
H
---- -
Read/Reset 4
000F5556
H
AAAA
H
000EAAAA
H
5555
H
000F5556
H
F0F0
H
RA RD - -
Program 4
000F5556
H
AAAA
H
000EAAAA
H
5555
H
000F5556
H
A0A0
H
PA PD
000EAAAA
H
5555
H
000E5556H
1010
H
Chip Erasing 6
000F5556
H
AAAA
H
000EAAAA
H
5555
H
000F5556
H
8080
H
000F5556
H
AAAA
H
000EAAAA
H
5555
H
SA
3030
H
Sector Erasing 6
000F5556
H
AAAA
H
000EAAAA
H
5555
H
000F5556
H
8080
H
000F5556
H
AAAA
H
--
Sector Erasing being Suspended
XXXXXXXX
H
B0B0
H
---- -
Sector Erasing being Restarted
XXXXXXXX
H
3030
H
---- -