c8051t617 Silicon Laboratories, c8051t617 Datasheet - Page 107

• Manufacturer Part Number: c8051t617
• Description: Mixed Signal Byte-programmable Eprom Mcu
• Manufacturer: Silicon Laboratories

11.2. Security Options
The C8051T610/1/2/3/4/5/6/7 devices provide security options to prevent unauthorized viewing of proprie-
tary program code and constants. A security byte stored at location 0x3FFF in EPROM address space can
be used to lock the program memory from being read or written across the C2 interface. The lock byte can
always be read regardless of the security settings. Table 11.2 shows the security byte decoding. See
Figure 11.1 for the program memory map and security byte locations for each device.
Important Note: Once the security byte has been written, there are no means of unlocking the
device. Locking memory from write access should be performed only after all other code has been
successfully programmed to memory.
Bits
7–4
3–0
Figure 11.1. EPROM Program Memory Map
C8051T610/1/6/7
EPROM Memory
Security Byte
15872 Bytes
Write Lock: Clearing any of these bits to logic 0 prevents all code
memory from being written across the C2 interface.
Read Lock: Clearing any of these bits to logic 0 prevents all code
memory from being read across the C2 interface.
Table 11.2. Security Byte Decoding
Reserved
0x3FFF
0x3FFE
0x3E00
0x3DFF
0x0000
Rev. 0.3
C8051T610/1/2/3/4/5/6/7
C8051T612/3/4/5
Description
EPROM Memory
Security Byte
8192 Bytes
Reserved
0x3FFF
0x3FFE
0x2000
0x1FFF
0x0000
107