C8051F312 Silicon Laboratories Inc, C8051F312 Datasheet - Page 114

• Manufacturer Part Number: C8051F312
• Description: IC 8051 MCU 8K FLASH 32LQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F31xr

Specifications of C8051F312

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 29
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 21x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: 336-1151

C8051F310/1/2/3/4/5/6/7
The level of Flash security depends on the Flash access method. The three Flash access methods that
can be restricted are reads, writes, and erases from the C2 debug interface, user firmware executing on
unlocked pages, and user firmware executing on locked pages. Table 10.2 summarizes the Flash security
features of the C8051F31x devices.
114
Read, Write or Erase unlocked pages
(except page with Lock Byte)
Read, Write or Erase locked pages
(except page with Lock Byte)
Read or Write page containing Lock Byte
(if no pages are locked)
Read or Write page containing Lock Byte
(if any page is locked)
Read contents of Lock Byte
(if no pages are locked)
Read contents of Lock Byte
(if any page is locked)
Erase page containing Lock Byte
(if no pages are locked)
Erase page containing Lock Byte - Unlock all
pages (if any page is locked)
Lock additional pages
(change '1's to '0's in the Lock Byte)
Unlock individual pages
(change '0's to '1's in the Lock Byte)
Read, Write or Erase Reserved Area

C2 Device Erase - Erases all Flash pages including the page containing the Lock Byte.
Flash Error Reset - Not permitted; Causes Flash Error Device Reset (FERROR bit in RSTSRC is '1' after
reset).
- All prohibited operations that are performed via the C2 interface are ignored (do not cause device reset).
- Locking any Flash page also locks the page containing the Lock Byte.
- Once written to, the Lock Byte cannot be modified except by performing a C2 Device Erase.
- If user code writes to the Lock Byte, the Lock does not take effect until the next device reset.
Action
Table 10.2. Flash Security Summary
Rev. 1.7
Not Permitted
Not Permitted
Not Permitted
Not Permitted
Not Permitted
Not Permitted
Erase Only
C2 Debug
C2 Device
Permitted
Permitted
Permitted
Permitted
Interface
an unlocked page
Flash Error Reset
Flash Error Reset
Flash Error Reset
Flash Error Reset Flash Error Reset
Flash Error Reset Flash Error Reset
Flash Error Reset Flash Error Reset
Flash Error Reset Flash Error Reset
Flash Error Reset Flash Error Reset
User Firmware executing from:
Permitted
Permitted
Permitted
a locked page
Permitted
Permitted
Permitted
Permitted
Permitted
Permitted