mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 109

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

2.4.1.3.3
The program command is used to program a previously erased word in the Flash memory using an
embedded algorithm. If the word to be programmed is in a protected area of the Flash block, the PVIOL
flag in the FSTAT register will set and the program command will not launch. After the program command
has successfully launched, the CCIF flag in the FSTAT register will set after the program operation has
completed unless a second command has been buffered.
A summary of the launching of a program operation is shown in
Freescale Semiconductor
Clock Register
Loaded
Check
Program Command
Protection
Violation Check
Access
Error Check
Address, Data,
Command
Buffer Empty Check
Bit Polling for
Command
Completion Check
Read: Register FCLKDIV
1.
2.
3.
Bit FDIVLD set?
Figure 2-25. Example Program Command Flow
yes
Write: Flash Address and
Program Data
Write: Register FCMD
Program Command 0x20
Write: Register FSTAT
Clear bit CBEIF 0x80
Read: Register FSTAT
no
no
MC9S12E256 Data Sheet, Rev. 1.08
no
yes
ACCERR
PVIOL
CBEIF
Set?
CCIF
Set?
EXIT
Write: Register FCLKDIV
Set?
Bit
Set?
Bit
Bit
Bit
no
yes
yes
yes
no
Clear bit PVIOL 0x20
Write: Register FSTAT
Clear bit ACCERR 0x10
Write: Register FSTAT
NOTE: command write sequence
aborted by writing 0x00 to
FSTAT register.
NOTE: command write sequence
aborted by writing 0x00 to
FSTAT register.
Read: Register FSTAT
Figure
Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
2-25.
Next Write?
yes
no
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