
Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
MC9S12HZ256 Data Sheet, Rev. 2.05
84
Freescale Semiconductor
Figure 2-24. Example Data Compress Command Flow
Write: Register FCLKDIV
Read: Register FCLKDIV
Bit FDIVLD set?
Write: Flash address to start
Write: Register FCMD
Data Compress Command 0x06
Write: Register FSTAT
yes
no
Clear bit CBEIF 0x80
Clock Register
Loaded
Check
1.
2.
3.
Clear bit ACCERR 0x10
Write: Register FSTAT
yes
no
Access
Error Check
Read: Register FSTAT
no
EXIT
compression and number of
Bit Polling for
Command
Completion Check
Read: Register FSTAT
yes
NOTE: command write sequence
aborted by writing 0x00 to
FSTAT register.
NOTE: command write sequence
aborted by writing 0x00 to
FSTAT register.
CCIF
Set?
Bit
ACCERR
Set?
Bit
word addresses to compress
Read: Register FDATA
Data Compress Signature
no
Erase and Reprogram
yes
Signature
Valid?
Signature
Flash Region Compressed
Compared to
Known Value