ST10F272M-4QR3 STMicroelectronics, ST10F272M-4QR3 Datasheet - Page 39

• Manufacturer Part Number: ST10F272M-4QR3
• Description: MCU 16BIT 256K FLASH 144-PQFP
• Manufacturer: STMicroelectronics
• Series: ST10r

Specifications of ST10F272M-4QR3

• Core Processor: ST10
• Core Size: 16-Bit
• Speed: 40MHz
• Connectivity: ASC, CAN, EBI/EMI, I²C, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 111
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 20K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 24x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 144-MQFP, 144-PQFP
• Processor Series: ST10F27x
• Core: ST10
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

ST10F272M
5.5.8
5.5.9
5.6
Note:
When the access protection is enabled, Flash registers can not be written, so no
program/erase operation can be run on IFlash. To enable the access to registers again, the
temporary access unprotection procedure has to be followed (see
Write protection
The Flash modules have one level of write protections: each sector of each bank of each
Flash module can be software write protected by programming at 0 the related bit W0Px in
FNVWPIRL register.
Temporary unprotection
Bits W0Px of FNVWPIRL can be temporarily unprotected by executing the set protection
operation and by writing 1 into these bits.
To restore the write protection bits it is necessary to reset the microcontroller or to execute a
set protection operation and write 0 into the desired bits.
In reality, when a temporary write unprotection operation is executed, the corresponding
volatile register is written to 1, while the non-volatile registers bits previously written to 0 (for
a protection set operation), will continue to maintain the 0. For this reason, the user software
must be in charge to track the current write protection status (for instance using a specific
RAM area), it is not possible to deduce it by reading the non-volatile register content (a
temporary unprotection cannot be detected).
To temporarily unprotect the Flash when the access protection is active, it is necessary to
set to ‘1’ the bit TAUB in XFVTAUR0. This bit can be set to ‘1’ only while executing from
Flash: In this way only an instruction executed from Flash can unprotect the Flash itself.
To restore the access protection, it is necessary to reset the microcontroller or to write at 0
the bit TAUB in XFVTAUR0.
Write operation examples
In the following, examples for each kind of Flash write operation are presented.
The write operation commands must be executed from another memory (internal RAM or
external memory), as in ST10F269 device. In fact, due to IBus characteristics, it is not
possible to perform write operation in Flash while fetching code from Flash.
Moreover, direct addressing is not allowed for write accesses to IFlash control registers.
This means that both address and data for a writing operation must be loaded in one of
ST10 GPR register (R0...R15).
Write operation on IBus registers is 16 bits wide.
Section
Internal Flash memory
5.5.9).
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