AN2400 Freescale Semiconductor / Motorola, AN2400 Datasheet - Page 9

• Manufacturer Part Number: AN2400
• Description: HCS12 NVM Guidelines
• Manufacturer: Freescale Semiconductor / Motorola

Flash Command
Register
MOTOROLA
Command
ACCERR — Access Error
BLANK — Erased Verification
Valid commands which may be written to the Flash or EEPROM Command
registers in Normal modes are shown in
Commands. Any other value will cause the ACCERR bit in ESTAT to be set.
The Flash Command register is banked on microcontrollers that have multiple
Flash blocks. That is, each Flash block has an independent Flash Command
register but each Flash Command register is accessed at the same address.
The active Block is selected by means of the BKSEL bits in the FCNFG
register.
1. An erase sector is 4 bytes for EEPROM, 1024 bytes for a 128k byte Flash block and 512
2. The Sector Modify command is applicable to EEPROM only.
The ACCERR flag indicates that an illegal access to the Flash or EEPROM
has occurred. The ACCERR flag must be cleared by writing a ‘1’ to
ACCERR before starting a new command sequence.
The BLANK flag indicates the result of an Erase Verify command. The
BLANK flag is cleared by hardware when the CBEIF flag is cleared. This flag
is read only.
Freescale Semiconductor, Inc.
bytes for all other Flash blocks.
$05
$20
$40
$41
$60
For More Information On This Product,
1 = Access error has occurred.
0 = No access error.
1 = Flash/EEPROM verified as erased by Erase Verify command.
0 = If an Erase Verify command has been executed, the Flash or
EEPROM is not erased.
Erase Verify
Program
Sector Erase
Mass Erase
Sector Modify
Go to: www.freescale.com
HCS12 NVM Guidelines
Table 2. Valid Flash/EEPROM Commands
Name
1
2
BLANK bit in ESTAT will be set on command
Program a word (2 bytes)
Erase a sector.
Erase an entire block.
Erase a sector (4 bytes), program a word (2 bytes)
completion if the entire EEPROM block is erased.
Table 2. Valid Flash/EEPROM
Description
Split-Gate Flash Memory
AN2400/D
9