mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 106

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
2.4.1.3.1
The erase verify operation is used to confirm that a Flash block is erased. After launching the erase verify
command, the CCIF flag in the FSTAT register will set after the operation has completed unless a second
command has been buffered. The number of bus cycles required to execute the erase verify operation is
equal to the number of addresses in the Flash block plus 12 bus cycles as measured from the time the
CBEIF flag is cleared until the CCIF flag is set. The result of the erase verify operation is reflected in the
state of the BLANK flag in the FSTAT register. If the BLANK flag is set in the FSTAT register, the Flash
memory is erased.
106
Erase Verify Command
Clock Register
Loaded
Check
Access
Error Check
Bit Polling for
Command
Completion Check
Read: Register FCLKDIV
Figure 2-23. Example Erase Verify Command Flow
1.
2.
3.
Bit FDIVLD set?
yes
Write: Flash Block Address
and Dummy Data
Erase Verify Command 0x05
Write: Register FSTAT
Clear bit CBEIF 0x80
Write: Register FCMD
MC9S12E256 Data Sheet, Rev. 1.08
Read: Register FSTAT
ACCERR
no
yes
yes
BLANK
Set?
Write: Register FCLKDIV
Bit
CCIF
Set?
Set?
EXIT
Bit
Bit
no
yes
no
no
NOTE: command write sequence
aborted by writing 0x00 to
FSTAT register.
NOTE: command write sequence
aborted by writing 0x00 to
FSTAT register.
Clear bit ACCERR 0x10
Write: Register FSTAT
Flash Block Not Erased;
Mass Erase Flash Block
Read: Register FSTAT
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