Freescale Semiconductor MCF51QE128RM manual Flash Commands, Erase Verify Command, Fcmd NVM

Chapter 4 Memory

2.Write a valid command to the FCMD register.

3.Clear the FCBEF flag in the FSTAT register by writing a 1 to FCBEF to launch the command.

After a command is launched, the completion of the command operation is indicated by the setting of FSTAT[FCCF]. The FCCF flag sets upon completion of all active and buffered burst program commands.

4.5.2Flash Commands

Table 4-16summarizes the valid flash commands along with the effects of the commands on the flash block.

		Table 4-16. Flash Command Description
FCMD	NVM	Function on Flash Memory
	Command
0x05	Erase Verify	Verify all memory bytes in the flash array memory are erased.
		If the flash array memory is erased, FSTAT[FBLANK] sets upon command completion.
0x20	Program	Program an address in the flash array.
0x25	Burst Program	Program an address in the flash array with the internal address incrementing after the
		program operation.
0x40	Sector Erase	Erase all memory bytes in a sector of the flash array.
0x41	Mass Erase	Erase all memory bytes in the flash array.
		A mass erase of the full flash array is only possible when no protection is enabled prior
		to launching the command.

CAUTION

A flash block address must be in the erased state before being programmed. Cumulative programming of bits within a flash block address is not allowed except for status field updates required in EEPROM emulation applications.

4.5.2.1Erase Verify Command

The erase verify operation verifies that the entire flash array memory is erased.

An example flow to execute the erase verify operation is shown in Figure 4-10. The erase verify command write sequence is as follows:

1.Write to an aligned flash block address to start the command write sequence for the erase verify command. The address and data written are ignored.

2.Write the erase verify command, 0x05, to the FCMD register.

3.Clear the FCBEF flag in the FSTAT register by writing a 1 to FCBEF to launch the erase verify command.

After launching the erase verify command, FSTAT[FCCF] sets after the operation has completed. The number of bus cycles required to execute the erase verify operation is equal to the number of addresses in the flash array memory plus several bus cycles as measured from the time the FCBEF flag is cleared until the FCCF flag is set. Upon completion of the erase verify operation, FSTAT[FBLANK] is set if all addresses in the flash array memory are verified to be erased. If any address in the flash array memory is not erased, the erase verify operation terminates and FSTAT[FBLANK] remains cleared.

MCF51QE128 MCU Series Reference Manual, Rev. 3

80 Freescale Semiconductor

Get the latest version from freescale.com