MC9S08SG8 Datasheet, PDF (58/310 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 4 Memory
Table 4-12. FSTAT Register Field Descriptions (continued)
Field
Description
4
FACCERR
Access Error Flag — FACCERR is set automatically when the proper command sequence is not obeyed exactly
(the erroneous command is ignored), if a program or erase operation is attempted before the FCDIV register has
been initialized, or if the MCU enters stop while a command was in progress. For a more detailed discussion of
the exact actions that are considered access errors, see Section 4.5.5, “Access Errors.” FACCERR is cleared by
writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or effect.
0 No access error.
1 An access error has occurred.
2
FBLANK
FLASH Verified as All Blank (erased) Flag — FBLANK is set automatically at the conclusion of a blank check
command if the entire FLASH array was verified to be erased. FBLANK is cleared by clearing FCBEF to write a
new valid command. Writing to FBLANK has no meaning or effect.
0 After a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the FLASH array is not
completely erased.
1 After a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the FLASH array is
completely erased (all 0xFF).
4.7.6 FLASH Command Register (FCMD)
Only five command codes are recognized in normal user modes as shown in Table 4-13. Refer to Section
4.5.3, “Program and Erase Command Execution,” for a detailed discussion of FLASH programming and
erase operations.
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
W
FCMD
Reset
0
0
0
0
0
0
0
0
Figure 4-10. FLASH Command Register (FCMD)
Table 4-13. FLASH Commands
Command
Blank check
Byte program
Byte program — burst mode
Page erase (512 bytes/page)
Mass erase (all FLASH)
FCMD
0x05
0x20
0x25
0x40
0x41
Equate File Label
mBlank
mByteProg
mBurstProg
mPageErase
mMassErase
All other command codes are illegal and generate an access error.
It is not necessary to perform a blank check command after a mass erase operation. Only blank check is
required as part of the security unlocking mechanism.
MC9S08SG8 MCU Series Data Sheet, Rev. 0
58
PRELIMINARY
Freescale Semiconductor