Fujitsu FR81S User Manual
CHAPTER 45: FLASH MEMORY
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : FLASH MEMORY
FUJITSU SEMICONDUCTOR CONFIDENTIAL
17
4.1. Flash Control Register : FCTLR (Flash ConTroL
Register)
The bit configuration of the flash control register is shown below.
This register configures the access control to flash.
FCTLR : Address 0840
H
(Access : Half-word)
bit15
bit14
bit13
bit12
bit11
bit10
bit9
bit8
Reserved
FWE
Reserved
FSZ[1:0]
FAW[1:0]
Initial value
1
0
-
-
1
0
0
0
Attribute R1,WX
R/W
RX,W0
RX,W0
R/W
R/W
R/W
R/W
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
FDSBL
Reserved
RDYF
Reserved
Initial value
0
-
-
0
-
-
-
-
Attribute
R/W
RX,W0
RX,W0
R/W
RX,W0
RX,W0
RX,W0
RX,W0
[bit15] Reserved
This bit is reserved. This bit always reads out as "1". Writing has no effect on the operation.
[bit14] FWE (Flash Write Enable) : Flash Write Enable
It is the write enable bit to flash. Setting this bit configures CPU programming mode. Use the FSTR:FRDY
bit to check whether or not writing is enabled.
If this bit is set, the ECC error detection and data correcting function will be disabled for data fetching to
the flash memory.
FWE
Description
0
Flash write disabled (Initial value)
1
Flash write enabled
Note:
When writing to FLASH, instruction fetch from FLASH is disabled.
[bit13, bit12] Reserved
These bits are reserved. The read value is undefined. When writing, always write "0" to these bits.
[bit11, bit10] FSZ[1:0] (Flash write access SiZe) : Flash write access size setting
The FLASH write access size at CPU mode is specified. Be sure to write in the specified bit count of the
access width. These two bits, bit11 and bit12, do not influence the reading access size. 32-bit Read is done
to the FLASH macro whenever it is read. When the wait cycle is inserted by the FAW bit, it becomes 64-bit
read access.
MB91520 Series
MN705-00010-1v0-E
1938