Datasheet

When the FCLKDIV register is written, the FCLKDIV[FDIVLD] bit is set automatically.

If the FCLKDIV[FDIVLD] bit is 0, the FCLKDIV register has not been written since the

last reset. If the FCLKDIV register has not been written, any flash and EEPROM

program or erase command loaded during a command write sequence will not execute

and the FSTAT[ACCERR] bit will be set.

4.5.2.4.2 Command write sequence

The memory controller will launch all valid flash and EEPROM commands entered using

a command write sequence.

Before launching a command, the FSTAT[ACCERR] and FSTAT[FPVIOL] bits must be

clear and the FSTAT[CCIF] flag will be tested to determine the status of the current

command write sequence. If FSTAT[CCIF] is 0, indicating that the previous command

write sequence is still active, a new command write sequence cannot be started and all

writes to the FCCOB register are ignored.

The FCCOB parameter fields must be loaded with all required parameters for the flash

and EEPROM command being executed. Access to the FCCOB parameter fields is

controlled via FCCOBIX[CCOBIX] bits.

Flash and EEPROM command mode uses the indexed FCCOB register to provide a

command code and its relevant parameters to the memory controller. First, the user must

set up all required FCCOB field. Then they can initiate the command's execution by

writing a 1 to the FSTAT[CCIF] bit. This action clears the CCIF command completion

flag to 0. When the user clears the FSTAT[CCIF] bit all FCCOB parameter field are

locked and cannot be changed by the user until the command completes (evidenced by

the memory controller returning FSTAT[CCIF] to1). Some commands return information

to the FCCOB register array.

The generic format for the FCCOB parameter fields in flash and EEPROM command

mode is shown in the following table. The return values are available for reading after the

FSTAT[CCIF] flag has been returned to 1 by the memory controller. Writes to the

unimplemented parameter fields, FCCOBIX[CCOBIX] =110b and FCCOBIX[CCOBIX]

= 111b, are ignored with read from these fields returning 0x0000.

The table below shows the generic flash command format. The high byte of the first word

in the CCOB array contains the command code, followed by the parameters for this

specific flash command. For details on the FCCOB settings required by each command,

see the flash command descriptions in Flash and EEPROM command summary .

Flash and EEPROM

MC9S08PA60 Reference Manual, Rev. 1, 9/2012

80 Freescale Semiconductor, Inc.