R8C/38T-A Group
26. Flash Memory
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0241EJ0010 Rev.0.10
Page 643 of 730
Aug 05, 2011
26.5.4
Suspend Operation
The suspend function halts the auto-erase operation temporarily during auto-erasure.
When auto-erasure of any block in data flash is suspended, auto-programming and reading of another block
can be executed.
When auto-erasure of data flash is suspended, auto-programming and reading of program ROM can be
executed.
When auto-erasure of any block in program ROM is suspended, auto-programming and reading of another
block can be executed.
When auto-erasure of program ROM is suspended, auto-programming and reading of data flash can be
executed.
To check the suspend, verify that the FST7 bit in the FST register is set to 1 (ready), and then verify that the
FST6 bit in the FST register is set to 1 (during erase-suspend) to confirm whether erasure has been suspended.
When the FST6 bit is set to 0 (other than erase-suspend), erasure has completed.
Notes:
1. E indicates operation is enabled by using the suspend function, D indicates operation is disabled, and N/A indicates no combination is available.
2. Operation cannot be suspended during programming.
3. The block erase command can be executed for erasure. The program, lock bit program, and read lock bit status commands can be executed for
programming.
The clear status register command can be executed when the FST7 bit in the FST register is set to 1 (ready).
The block blank check operation is disabled during suspend.
4. The MCU enters read array mode immediately after entering erase-suspend.
5. Applicable only to products with on-chip data flash.
6. The program ROM area can be read with the BGO function while programming or block erasing data flash.
Figure 26.5
Suspend Operation Timing
Table 26.5
Executable Operation during Suspend
Operation during Suspend
Data flash
(Block during erasure
execution before entering
suspend)
Data flash
(Block during no erasure
execution before entering
suspend)
Program ROM
(Block during erasure
execution before entering
suspend)
Program ROM
(Block during no erasure
execution before entering
suspend)
Erase
Program
Read
Erase
Program
Read
Erase
Program
Read
Erase
Program
Read
Areas
during
erasure
execution
before
entering
suspend
Data flash
D
E
N/A
D
E
Program
ROM
N/A
D
E
D
E
Data flash
Data
read
Suspend
(readable)
Program
Erase
Program ROM
User
program
Command
issue
User
program
Set
FMR21
bit to 1
Command
issue
User
program
Set
FMR21
bit to 0
User
program
User
program
FMR21 bit in
FMR2 register
FST7 bit in
FST register
FST6 bit in
FST register
RDYSTI bit in
FST register
Flash ready
interrupt
handling
Suspend
(readable)
Flash
ready
interrupt
handling
User
program
Flash
ready
interrupt
handling
Suspend
(readable)
Set to 0 by a program
td(SR-SUS)
1 is set automatically
Erase
1 is set automatically