User Security Bytes - Philips P89LPC920 User Manual

Philips Semiconductors
FLASH MEMORY

User security bytes

This device has three security bits associated with each of its eight sectors, as shown in Figure 6.
SECx
Address: xxxxh
Unprogrammed value: 00h
BIT SYMBOL
SECx.7-3 -
SECx.2 EDISx
SECx.1 SPEDISx
SECx.0 MOVCDISx
Table 15-5: Effects of Security Bits
EDISx SPEDISx MOVCDISx
0 0
0 0
0 1
1 x
2003 Dec 8
7 6
-
FUNCTION
Reserved (should remain unprogrammed at zero).
Erase Disable ISP. Disables the ability to perform an erase of sector "x" in ISP or IAP
mode.. When programmed, this bit and sector x can only be erased by a 'global' erase
command using a commercial programmer . This bit and sector x CANNOT be erased in
ISP or IAP modes.
Sector Program Erase Disable x. Disables program or erase of all or part of sector x.
This bit and sector x are erased by either a sector erase command (ISP, IAP, commercial
programmer) or a 'global' erase command (commercial programmer).
MOVC Disable. Disables the MOVC command for sector x. Any MOVC that attempts to
read a byte in a MOVC protected sector will return invalid data. This bit can only be erased
when sector x is erased.
Figure 6: User sector Security Bytes (SEC0, ..., SEC7)
0 None.
Security violation flag set for sector CRC calculation for the specific sector. Security
violation flag set for global CRC calculation if any MOVCDISx bit is set. Cycle aborted.
1
Memory contents unchanged. CRC invalid. Program/erase commands will not result
in a security violation.
Security violation flag set for program commands or an erase page command. Cycle
x
aborted. Memory contents unchanged. Sector erase and global erase are allowed.
Security violation flag set for program or erase commands. Cycle aborted. Memory
x
contents unchanged. Global erase is allowed.
5 4
- - -
Effects on Programming
110
User's Manual - Preliminary -
P89LPC920/921/922
3 2 1
- EDISx SPEDISxMOVCDISx
0