7.1.1
7.1.2
User Space
Boot Space
This space is composed of a 64K Bytes Flash memory organized in 512 pages of 128 Bytes. It
contains the user’s application code. This space can be read or written by both software and
hardware modes.
This space is composed of a 4K Bytes Flash memory. It contains the bootloader for In-System
Programming and the routines for In-System Application Programming.
This space can only be read or written by hardware mode using a parallel programming tool.
7.1.3
Hardware Security Space
This space is composed of one byte: the Hardware Security Byte (HSB see Table 7) divided in
two separate nibbles see Table 7. The MSN contains the X2 mode configuration bit and the Boot
Loader Jump Bit as detailed in section “Boot Memory Execution” and can be written by software
while the LSN contains the lock system level to protect the memory content against piracy as
detailed in section “Hardware Security System” and can only be written by hardware.
7.1.4
Extra Row Space
This space is composed of two Bytes:
•
The Software Boot Vector (SBV see Table 8).
This byte is used by the software bootloader to build the boot address.
•
The Software Security Byte (SSB see Figure ).
This byte is used to lock the execution of some bootloader commands.
7.2
Hardware Security System
The AT89C5132 implements three lock Bits LB2:0 in the LSN of HSB (see Table 7) providing
three levels of security for user’s program as described in Table 7 while the AT83C51SND1C is
always set in read disabled mode.
•
•
•
•
Level 0 is the level of an erased part and does not enable any security feature.
Level 1 locks the hardware programming of both user and boot memories.
Level 2 locks hardware verifying of both user and boot memories.
Level 3 locks the external execution.
Table 5. Lock Bit Features(1)
Internal
External
Hardware
Verifying
Hardware
Software
Level LB2(2) LB1 LB0
Execution
Execution
Programming Programming
0
1
U
U
U
P
U
U
P
X
U
P
X
X
Enable
Enable
Enable
Enable
Disable
Enable
Enable
Disable
Disable
Enable
Disable
Disable
Disable
Enable
Enable
Enable
Enable
Enable
2
Enable
3(3)
Enable
Notes: 1. U means unprogrammed, P means programmed and X means don’t care (programmed or
unprogrammed).
2. LB2 is not implemented in the AT89C5132 products.
3. AT89C5132 products are delivered with third level programmed to ensure that the code pro-
grammed by software using ISP or user’s bootloader is secured from any hardware piracy.
18
AT89C5132
4173E–USB–09/07
ATMEL [ ATMEL ]
