AN2153 Freescale Semiconductor / Motorola, AN2153 Datasheet - Page 6

• Manufacturer Part Number: AN2153
• Description: A Serial Bootloader for Reprogramming the MC9S12DP256 FLASH Memory
• Manufacturer: Freescale Semiconductor / Motorola

Application Note
6
The FPOPEN bit in each FPROT register determines whether the entire
FLASH block or subsections of it can be programmed or erased. When
the FPOPEN bit is erased (1), the remainder of the bits in the register
determine the state of protection and the size of each protected block. In
its programmed state (0), the entire FLASH block is protected and the
state of the remaining bits within the FPROT register is irrelevant.
The FPHDIS and FPLDIS bits determine the protection state of the
upper and lower areas within each 64-K block respectively. The erased
state of these bits allows erasure and programming of the two protected
areas and renders the state of the FPHS[1:0] and FPLS[1:0] bits
immaterial. When either of these bits is programmed, the FPHS[1:0] and
FPLS[1:0] bits determine the size of the upper and lower protected
areas. The tables in
FPHS[1:0] and FPLS[1:0] bits and the size of the protected area
selected by each.
Freescale Semiconductor, Inc.
Figure 3. FLASH Protection and Security Memory Locations
For More Information On This Product,
$FF00–$FF07
$FF08–$FF09
Go to: www.freescale.com
Address
$FF0C
$FF0D
$FF0A
$FF0B
$FF0E
$FF0F
Figure 4
Security back door comparison key
Protection byte for FLASH block 3
Protection byte for FLASH block 2
Protection byte for FLASH block 1
Protection byte for FLASH block 0
summarize the combinations of the
Security byte
Description
Reserved
Reserved
MOTOROLA
AN2153