MCF51QE128 MCU Series Reference Manual, Rev. 3
Freescale Semiconductor 77
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Chapter 4 Memory

4.4.2.6 Flash Command Register (FCMD)

The FCMD register is the flash command register. All FCMD bits are readable and writable during a
command write sequence while bit 7 reads 0 and is not writable.
4.5 Function Description

4.5.1 Flash Command Operations

Flash command operations execute program, erase, and erase verify algorithms described in this section.
The program and erase algorithms are controlled by the flash memory controller whose time base, FCLK,
is derived from the bus clock via a programmable divider.
The next sections describe:
1. How to write the FCDIV register to set FCLK
2. Command write sequences to program, erase, and erase verify operations on the flash memory
3. Valid flash commands
2
FBLANK
Flag Indicating the Erase Verify Operation Status. When the FCCF flag is set after completion of an erase
verify command, the FBLANK flag indicates the result of the erase verify operation. The FBLANK flag is cleared
by the flash module when FCBEF is cleared as part of a new valid command write sequence. Writing to the
FBLANK flag has no effect on FBLANK.
0 Flash block verified as not erased.
1 Flash block verified as erased.
1–0 Reserved, should be cleared.
76543210
R0 FCMD
W
Reset00000000
Figure 4-8. Flash Command Register (FCMD)
Table 4-15. FCMD Field Descriptions
Field Description
7 Reserved, should be cleared.
6–0
FCMD
Flash Command. Valid flash commands are shown below. Writing any command other than those listed sets
the FACCERR flag in the FSTAT register.
0x05 Erase Verify
0x20 Program
0x25 Burst Program
0x40 Sector Erase
0x41 Mass Erase
Table 4-14. FSTAT Field Descriptions (continued)
Field Description