Fujitsu FR81S User Manual
CHAPTER 46: WORKFLASH MEMORY
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : WORKFLASH MEMORY
FUJITSU SEMICONDUCTOR CONFIDENTIAL
20
Note:
Do as follows to LSB 2-bit of the sector address (SA) to input when the command address and the sector
erase command are issued.
- When half-word access : 2'b00
- When byte access : 2’b01 or 2’b11
Example 1:
When byte access and command address = (LSB 2-bit of the standard command address is changed to
2’b01.)
AA8
H
→ AA9
H
, 554
H
→ 555
H
, and SA → { SA[31:2] and 2'b01 }
(SA: When the sector erase command is issued, it is an arbitrary address in the input erase target sector)
Example 2:
When byte access and command address = (LSB 2-bit of the standard command address is changed to
2’b11.)
AA8
H
→ AAB
H
, 554
H
→ 577
H
, and SA → { SA[31:2] and 2'b11 }
(SA: When the sector erase command is issued, it is an arbitrary address in the input erase target sector)
Note:
When the wrong address value and data value are written or writing is performed in the wrong sequence,
commands that have been written are cleared.
Reset Command
When the reset command is given to the target flash memory, a sequential input of each command shown in
Table 5-1 is cancelled, and another sequential input can be done again from the first time.
However, when each command is input to the last minute and automatic algorithm starts, automatic
algorithm cannot be discontinued by this reset command.
If the execution of the automatic algorithm exceeds the timing limit, the flash memory returns to the reset
state if a reset command is input.
Read Command
The flash memory can be read by sending read commands to the target sector. If a read command is issued,
the flash memory stays in read state until another command is issued.
Programming (Write) Command
If a write command is sent to the target sector four times in a row, the automatic program algorithm starts
and writes data to the flash memory. Programming (writing) of data can be performed in any order of
addresses or across a sector boundary. In the CPU programming mode, data is written in half-words. Once
the fourth write has finished, the automatic algorithm starts and the automatic write to flash memory is
started. After executing the automatic write algorithm command sequence, there is no need to control the
flash memory externally.
See "5.5 Write Command" for details on the actual operation.
MB91520 Series
MN705-00010-1v0-E
1991