MC9S12HZ256 Datasheet, PDF (111/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 3 2 Kbyte EEPROM Module (EETS2KV1)
Read: Register ECLKDIV
Clock Register
Written
Check
Bit EDIVLD set? ^no
yes
Write: Register ECLKDIV
1.
Write: Array Address and
Program Data
2.
Write: Register ECMD
Program Command 0x20
3.
Write: Register ESTAT
Clear bit CBEIF 0x80
Read: Register ESTAT
NOTE: command sequence
aborted by writing 0x00 to
ESTAT register.
NOTE: command sequence
aborted by writing 0x00 to
ESTAT register.
Protection
Violation Check
Access
Error Check
Address, Data,
Command
Buffer Empty Check
Bit
PVIOL
Set?
no
Bit
ACCERR
Set?
no
Bit
CBEIF
Set?
no
yes _{Write: Register ESTAT}
Clear bit PVIOL 0x20
yes _{Write: Register ESTAT}
Clear bit ACCERR 0x10
yes
yes
Next Write?
no
Bit Polling for
Command
Bit
CCIF
no
Completion Check
Set?
yes
Read: Register ESTAT
EXIT
Figure 3-18. Example Program Command Flow
MC9S12HZ256 Data Sheet, Rev. 2.04
Freescale Semiconductor
111