Chapter 4 Memory

 

 

Table 4-14. FSTAT Field Descriptions (continued)

 

 

 

Field

 

Description

 

 

2

Flag Indicating the Erase Verify Operation Status. When the FCCF flag is set after completion of an erase

FBLANK

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.

 

 

 

4.4.2.6Flash 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.

R

W

Reset

7

6

5

4

3

2

1

0

0

 

 

 

FCMD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

0

0

0

0

0

 

 

 

 

 

 

 

 

 

 

Figure 4-8. Flash Command Register (FCMD)

 

 

Table 4-15. FCMD Field Descriptions

 

 

 

Field

 

Description

 

 

7

Reserved, should be cleared.

 

 

6–0

Flash Command. Valid flash commands are shown below. Writing any command other than those listed sets

FCMD

the FACCERR flag in the FSTAT register.

 

0x05

Erase Verify

 

0x20

Program

 

0x25

Burst Program

 

0x40

Sector Erase

 

0x41

Mass Erase

 

 

 

4.5Function Description

4.5.1Flash 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

MCF51QE128 MCU Series Reference Manual, Rev. 3

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Freescale Semiconductor MCF51QE128RM manual Function Description, Flash Command Operations, Flash Command Register Fcmd