C8051F317-GMR Silicon Laboratories Inc, C8051F317-GMR Datasheet - Page 113

• Manufacturer Part Number: C8051F317-GMR
• Description: MCU 8-Bit C8051F31x 8051 CISC 16KB Flash 3.3V 24-Pin QFN EP T/R
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051F317-GMR

• Package: 24QFN EP
• Device Core: 8051
• Family Name: C8051F31x
• Maximum Speed: 25 MHz
• Ram Size: 1.25 KB
• Program Memory Size: 16 KB
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 21
• Interface Type: I2C/SMBus/SPI/UART
• On-chip Adc: 17-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4

10.3. Security Options
The CIP-51 provides security options to protect the Flash memory from inadvertent modification by soft-
ware as well as to prevent the viewing of proprietary program code and constants. The Program Store
Write Enable (bit PSWE in register PSCTL) and the Program Store Erase Enable (bit PSEE in register
PSCTL) bits protect the Flash memory from accidental modification by software. PSWE must be explicitly
set to ‘1’ before software can modify the Flash memory; both PSWE and PSEE must be set to ‘1’ before
software can erase Flash memory. Additional security features prevent proprietary program code and data
constants from being read or altered across the C2 interface.
A Security Lock Byte located at the last byte of Flash user space offers protection of the Flash program
memory from access (reads, writes, or erases) by unprotected code or the C2 interface. The Flash security
mechanism allows the user to lock n 512-byte Flash pages, starting at page 0 (addresses 0x0000 to
0x01FF), where n is the 1’s complement number represented by the Security Lock Byte. Note that the
page containing the Flash Security Lock Byte is unlocked when no other Flash pages are locked
(all bits of the Lock Byte are ‘1’) and locked when any other Flash pages are locked (any bit of the
Lock Byte is ‘0’). See the example below.
other FLASH pages
FLASH security lock
Locked when any
Flash pages locked:
according to the
Security Lock Byte:
Access limit set
Addresses locked:
1’s Complement:
are locked
byte
Unlocked FLASH Pages
C8051F310/1/6/7
Lock Byte
Reserved
Figure 10.1. Flash Program Memory Map
and 0x3C00 to 0x3DFF or 0x1E00 to 0x1FFF (Lock Byte Page)
3 (First two Flash pages + Lock Byte Page)
0x3E00
0x3DFF
0x3DFE
0x3C00
0x0000
0x0000 to 0x03FF (first two Flash pages)
Rev. 1.7
C8051F310/1/2/3/4/5/6/7
Unlocked FLASH Pages
C8051F312/3/4/5
00000010b
Lock Byte
Reserved
11111101b
0x2000
0x1FFF
0x1FFE
0x1E00
0x0000
organized in 512-byte
FLASH memory
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