C8051F901-GU Silicon Laboratories Inc, C8051F901-GU Datasheet - Page 134

• Manufacturer Part Number: C8051F901-GU
• Description: IC MCU 8BIT 8KB FLASH 24QSOP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F9xxr

Specifications of C8051F901-GU

• Program Memory Type: FLASH
• Program Memory Size: 8KB (8K x 8)
• Package / Case: 24-QSOP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 3.6 V
• Data Converters: A/D 15x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F9x
• Core: 8051
• Data Ram Size: 768 B
• Interface Type: UART
• Maximum Clock Frequency: 25 MHz
• Number Of Timers: 4
• Operating Supply Voltage: 0.9 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F912DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 24QSOP
• Device Core: 8051
• Family Name: C8051F90x
• Maximum Speed: 25 MHz
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1847-5

C8051F91x-C8051F90x
13.3. Security Options
The CIP-51 provides security options to protect the Flash memory from inadvertent modification by
software 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 1s 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).
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 13.1 summarizes the Flash security
features of the C8051F91x-C8051F90x devices.
134
0x0000
0x3BFE
0xFFFF
0x3C00
0x3BFF
0x3A00
Flash pages locked:
Security Lock Byte:
ones Complement:
Addresses locked:
16KB Flash Device
Unlocked Flash Pages
Lock Byte Page
(SFLE = 0)
Lock Byte
Reserved
Figure 13.1. Flash Program Memory Map (16 kB and 8 kB devices)
Locked when
set according
security lock
Flash pages
Access limit
to the Flash
are locked
any other
byte
0x0000 to 0x07FF (first four Flash pages) and
5 (First four Flash pages + Lock Byte Page)
Unlocked Flash Pages
8KB Flash Device
Lock Byte Page
0x3A00 to 0x3BFF (Lock Byte Page)
Rev. 1.0
(SFLE = 0)
Lock Byte
Reserved
0000 0100b
1111 1011b
0xFFFF
0x2000
0x1FFF
0x1FFE
0x1E00
0x0000
16/8 KB Flash Device
Scratchpad Area
(Data Only)
(SFLE = 1)
0x01FF
0x0000
organized in
512-byte
memory
pages
Flash