Datasheet

Chapter 4 Memory Map and Register Definition
MC9S08QD4 Series MCU Data Sheet, Rev. 6
Freescale Semiconductor 49
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.
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.
76543210
R00000000
WFCMD
Reset00000000
= Unimplemented or Reserved
Figure 4-10. Flash Command Register (FCMD)
Table 4-13. Flash Commands
Command FCMD Equate File Label
Blank check 0x05 mBlank
Byte program 0x20 mByteProg
Byte program — burst mode 0x25 mBurstProg
Page erase (512 bytes/page) 0x40 mPageErase
Mass erase (all flash) 0x41 mMassErase