Archive for September, 2012

PostHeaderIcon Reverse Engineering MCU ATTINY48V eeprom

We can reverse engineering MCU ATTINY48V eeprom, please view the MCU ATTINY48V features for your reference:
This section discusses the AVR core architecture in general. The main function of the CPU core is to ensure correct program execution. The CPU must therefore be able to access memories, perform calculations, control peripherals, and handle interrupts. In order to maximize performance and parallelism, the AVR uses a Harvard architecture – with separate memories and buses for program and data. Instructions in the program memory are executed with a single level pipelining if reverse engineering MCU eeprom.
While one instruction is being executed, the next instruction is pre-fetched from the program memory. This concept enables instructions to be executed in every clock cycle. The program memory is In System Reprogrammable eeprom memory. The fast-access Register File contains 32 x 8-bit general purpose working registers with a single clock cycle access time. This allows single-cycle ArithmetMCU LogMCU Unit (ALU) operation.
In a typMCUal ALU operation, two operands are output from the Register File, the operation is executed, and the result is stored back in the Register File – in one clock cycle. Six of the 32 registers can be used as three 16-bit indirect address register pointers for Data Space addressing – enabling effMCUient address calculations when reverse engineering MCU eeprom.
One of the these address pointers can also be used as an address pointer for look up tables in eeprom program memory. These added function registers are the 16-bit X-, Y-, and Z-register, described later in this section.
The ALU supports arithmetMCU and logMCU operations between registers or between a constant and a register. Single register operations can also be executed in the ALU. After an arithmetMCU operation, the Status Register is updated to reflect information about the result of the operation.
Program flow is provided by conditional and unconditional jump and call instructions, able to directly address the whole address space. Most AVR instructions have a single 16-bit word format. Every program memory address contains a 16- or 32-bit instruction after REVERSE ENGINEERING MICROCONTROLLER.

PostHeaderIcon Reverse Engineering IC firmware

The next possible way of reverse engineering IC firmware from a device is playing around with its interface signals and access protocols. Also, if a security protocol is wrongly implemented, that leaves a hole for the ic reverse engineering firmware people to exploit. Some microcontrollers and smartcards have a factory-test interface that provides access to on-chip memory and allows the manufacturer to test the device. If reverse engineering IC firmware can find a way of exploiting this interface, he can easily extract the information stored inside the chip. Normally information on test circuits is kept secret by the manufacturer, but an IC attacker can try applying different voltages and logic levels to the pins in the hope that it will put it into test mode. This sometimes works for microcontrollers but in smartcards such test circuitry is usually destroyed after use. Also, embedded software developers sometimes implement functions that allow downloading from internal memory for test and update purposes. That must be done in a way that prevents any access to the code without proper authentication, or so that the code can be sent out in encrypted form only.

PostHeaderIcon Discover IC code

The most widely used non-invasive discover IC code include playing around with the supply voltage and clock signal. Under-voltage and over-voltage IC code discover could be used to disable protection circuit or force a processor to do the wrong operation. For these reasons, some security processors have a voltage detection circuit, but this circuit cannot react to fast transients. Power and clock transients can also be used in some processors to affect the decoding and execution of individual instructions.

Another possible IC code discovery uses current analysis. We can measure with an analog-to-digital converter the fluctuations in the current consumed by the device. Drivers on the address and data bus often consist of up to a dozen parallel inverters per bit, each driving a large capacitive load. They cause a significant power-supply short circuit during any transition. Changing a single bus line from ‘0’ to ‘1’ or vice versa can contribute in the order of 0.5–1mA to the drain current right after the clock edge. So a 12-bit ADC is sufficient to estimate the number of bus bits that change at anyone time. SRAM write operations often generate the strongest signals.

PostHeaderIcon Recover Microcontroller ATMEGA324V Data

We can recover Microcontroller ATMEGA324V data, please view the Microcontroller ATMEGA324V features for your reference:

Pins XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can be configured for use as an On-Microcontroller Oscillator, as shown in Figure 22. Either a quartz crystal or a ceramic resonator may be used. This Crystal Oscillator is a full swing oscillator, with rail-to-rail swing on the XTAL2 output. This is useful for driving other clock inputs and in noisy environments. The current consumption is higher than the “Low Power Crystal Oscillator” if recover Microcontroller data.
Note that the Full Swing Crystal Oscillator will only operate for Vcc = 2.7 – 5.5 volts. C1 and C2 should always be equal for both crystals and resonators. The optimal value of the capacitors depends on the crystal or resonator in use, the amount of stray capacitance, and the electromagnetic noise of the environment.
Some initial guidelines for choosing capacitors for use with crystals are given in Table 12. For ceramic resonators, the capacitor values given by the manufacturer should be used.
The frequency ranges are preliminary values. Actual values are TBD.
If 8 MHz frequency exceeds the specification of the device (depends on VCC), the CKDIV8 Fuse can be programmed in order to divide the internal frequency by 8. It must be ensured that the resulting divided clock meets the frequency specification of the device when recover Microcontroller data.
These options should only be used when not operating close to the maximum frequency of the device, and only if frequency stability at start-up is not important for the application. These options are not suitable for crystals.
These options are intended for use with ceramic resonators and will ensure frequency stability at start-up. They can also be used with crystals when not operating close to the maximum frequency of the device, and if frequency stability at start-up is not important for the application.
The frequency ranges are preliminary values. Actual values are TBD.
This option should not be used with crystals, only with ceramic resonators.
If 8 MHz frequency exceeds the specification of the device (depends on VCC), the CKDIV8 Fuse can be programmed in order to divide the internal frequency by 8. It must be ensured that the resulting divided clock meets the frequency specification of the device before RECOVER MCU.

PostHeaderIcon Discover Chip Firmware

The next possible way of dicover chip firmware from a device is playing around with its interface signals and access protocols. Also, if a security protocol is wrongly implemented, that leaves a hole for the IC attacker to exploit. Some microcontrollers and smartcards have a factory-test interface that provides access to on-chip memory and allows the manufacturer to test the device. If an ic cracker can find a way of exploiting this interface, he can easily discover the firmware stored inside the chip. Normally information on test circuits is kept secret by the manufacturer, but an mcu cracker can try applying different voltages and logic levels to the pins in the hope that it will put it into test mode. This sometimes works for microcontrollers but in smartcards such test circuitry is usually destroyed after use. Also, embedded software developers sometimes implement functions that allow downloading from internal memory for test and update purposes. That must be done in a way that prevents any access to the code without proper authentication, or so that the code can be sent out in encrypted form only.

PostHeaderIcon Reverse Engineering MCU ATMEGA324PV Heximal

We can Reverse Engineering MCU ATMEGA324PV heximal, please view the MCU ATMEGA324PV features for your reference:
These options should only be used when not operating close to the maximum frequency of the device, and only if frequency stability at start-up is not important for the application. These options are not suitable for crystals.
These options are intended for use with ceramic resonators and will ensure frequency stability at start-up. They can also be used with crystals when not operating close to the maximum frequency of the device, and if frequency stability at start-up is not important for the application if Reverse Engineering MCU heximal.
The device can utilize a 32.768 kHz watch crystal as clock source by a dedicated Low Frequency Crystal Oscillator. The crystal should be connected as shown in Figure 22. When this Oscillator is selected, start-up times are determined by the SUT Fuses and CKSEL0.
The calibrated internal RC Oscillator by default provides a 8.0 MHz clock. The frequency is nominal value at 3V and 25°C. The device is shipped with the CKDIV8 Fuse programmed. See “System Clock Prescaler” on page 48 for more details. This clock may be selected as the system clock by programming the CKSEL Fuses as shown in Table.
If selected, it will operate with no external components. During reset, hardware loads the calibration byte into the OSCCAL Register and thereby automatically calibrates the RC Oscillator. At 3V and 25°C, this calibration gives a frequency of 8 MHz ± 1% when Reverse Engineering MCU heximal.
The oscillator can be calibrated to any frequency in the range 7.3 – 8.1 MHz within ±1% accuracy, by changing the OSCCAL register. When this Oscillator is used as the MCU clock, the Watchdog Oscillator will still be used for the Watchdog Timer and for the Reset Time-out. For more information on the pre-programmed calibration value when Reverse Engineering MCU heximal.
The device is shipped with this option selected.
The frequency ranges are preliminary values. Actual values are TBD.
If 8 MHz frequency exceeds the specification of the device (depends on VCC), the CKDIV8 Fuse can be programmed in order to divide the internal frequency by 8. When this Oscillator is selected, start-up times are determined by the SUT Fuses if Reverse Engineering MCU heximal.
The Oscillator Calibration Register is used to trim the Calibrated Internal RC Oscillator to remove process variations from the oscillator frequency. The factory-calibrated value is automatically written to this register during MCU reset, giving an oscillator frequency of 8.0 MHz at 25°C before Reverse Engineering MCU heximal.
The application software can write this register to change the oscillator frequency. The oscillator can be calibrated to any frequency in the range 7.3 – 8.1 MHz within ±1% accuracy. Calibration outside that range is not guaranteed after Reverse Engineering MICROCONTROLLER.

PostHeaderIcon Recover MCU ATMEGA324A Firmware

We can Recover MCU ATMEGA324A firmware, please view the MCU ATMEGA324A features for your reference:

Note that this oscillator is used to time EEPROM and Flash write accesses, and these write times will be affected accordingly. If the EEPROM or Flash are written, do not calibrate to more than 8.8 MHz. Otherwise, the EEPROM or Flash write may fail.
The CAL7 bit determines the range of operation for the oscillator. Setting this bit to 0 gives the lowest frequency range, setting this bit to 1 gives the highest frequency range. The two frequency ranges are overlapping, in other words a setting of OSCCAL = 0x7F gives a higher frequency than OSCCAL = 0x80 if Recover MCU firmware.
The CAL6..0 bits are used to tune the frequency within the selected range. A setting of 0x00 gives the lowest frequency in that range, and a setting of 0x7F gives the highest frequency in the range. Incrementing CAL6..0 by 1 will give a frequency increment of less than 2% in the frequency range 7.3 – 8.1 MHz before Recover MCU firmware.
The 128 kHz internal Oscillator is a low power Oscillator providing a clock of 128 kHz. The frequency is nominal at 3V and 25°C. This clock may be select as the system clock by programming the CKSEL Fuses to “11” as shown in Table 16.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in Table 17. To drive the device from an external clock source, XTAL1 should be driven as shown in Figure 24. To run the device on an external clock, the CKSEL Fuses must be programmed to “0000” when Recover MCU firmware.
When applying an external clock, it is required to avoid sudden changes in the applied clock frequency to ensure stable operation of the MCU. A variation in frequency of more than 2% from one clock cycle to the next can lead to unpredictable behavior. If changes of more than 2% is required, ensure that the MCU is kept in Reset during the changes.
Note that the System Clock Prescaler can be used to implement run-time changes of the internal clock frequency while still ensuring stable operation. Refer to “System Clock Prescaler” on page 48 for details. The device can output the system clock on the CLKO pin. To enable the output, the CKOUT Fuse has to be programmed before Recover MCU firmware.
This mode is suitable when the MCU clock is used to drive other circuits on the system. The clock also will be output during reset, and the normal operation of I/O pin will be overridden when the fuse is programmed. Any clock source, including the internal RC Oscillator, can be selected when the clock is output on CLKO. If the System Clock Prescaler is used, it is the divided system clock that is output after RECOVER MCU.

PostHeaderIcon Clone IC firmware

Another possible IC firmware clone uses current analysis. We can measure with an analog-to-digital converter the fluctuations in the current consumed by the device. Drivers on the address and data bus often consist of up to a dozen parallel inverters per bit, each driving a large capacitive load. They cause a significant power-supply short circuit during any transition. Changing a single bus line from ‘0’ to ‘1’ or vice versa can contribute in the order of 0.5–1mA to the drain current right after the clock edge. So a 12-bit ADC is sufficient to estimate the number of bus bits that change at anyone time. SRAM write operations often generate the strongest signals.

Another possible threat to secure devices is data remanence. This is the capability of volatile memory to retain information for some time after power is disconnected. Static RAM storing the same key for a long period of time can reveal it on next power on. Another possibility is to ‘freeze’ the memory by applying low temperature. In this case, static RAM can retain information for enough time to get access to the memory chip and read its contents. Data remanence can take place in non-volatile memories as well; the residual charge left on a floating gate transistor may be detected. For example, it could affect a threshold level or time-switching characteristics.

PostHeaderIcon Break Microcontroller ATMEAG324PA Binary

We can break Microcontroller ATMEAG324PA binary, please view the Microcontroller ATMEAG324PA features for your reference:

The device can operate its Timer/Counter2 from an external 32.768 kHz watch crystal or a external clock source. See Figure 22 on page 41 for crystal connection. Applying an external clock source to TOSC1 requires EXCLK in the ASSR Register written to logic one. See “Asynchronous operation of the Timer/Counter” on page 189 for further description on selecting external clock as input instead of a 32 kHz crystal.

The ATMEAG324PA has a system clock prescaler, and the system clock can be divided by setting the “Clock Prescale Register – CLKPR” on page 49. This feature can be used to decrease the system clock frequency and the power consumption when the requirement for processing power is low before break Microcontroller binary.
This can be used with all clock source options, and it will affect the clock frequency of the CPU and all synchronous peripherals. clkI/O, clkADC, clkCPU, and clkFLASH are divided by a factor after break Microcontroller binary.
When switching between prescaler settings, the System Clock Prescaler ensures that no glitches occurs in the clock system. It also ensures that no intermediate frequency is higher than neither the clock frequency corresponding to the previous setting, nor the clock frequency corresponding to the new setting before break Microcontroller binary.
The ripple counter that implements the prescaler runs at the frequency of the undivided clock, which may be faster than the CPU’s clock frequency. Hence, it is not possible to determine the state of the prescaler – even if it were readable, and the exact time it takes to switch from one clock division to the other cannot be exactly predicted. From the time the CLKPS values are written, it takes between T1 + T2 and T1 + 2 * T2 before the new clock frequency is active. In this interval, 2 active clock edges are produced. Here, T1 is the previous clock period, and T2 is the period corresponding to the new prescaler setting if break Microcontroller binary.
To avoid unintentional changes of clock frequency, a special write procedure must be followed to change the CLKPS bits:
Write the Clock Prescaler Change Enable (CLKPCE) bit to one and all other bits in CLKPR to zero.
Within four cycles, write the desired value to CLKPS while writing a zero to CLKPCE.
Interrupts must be disabled when changing prescaler setting to make sure the write procedure is not interrupted.
The CLKPCE bit must be written to logic one to enable change of the CLKPS bits. The CLKPCE bit is only updated when the other bits in CLKPR are simultaneously written to zero. CLKPCE is cleared by hardware four cycles after it is written or when CLKPS bits are written. Rewriting the CLKPCE bit within this time-out period does neither extend the time-out period, nor clear the CLKPCE bit before BREAK IC.

PostHeaderIcon decrypt IC firmware

The most widely used non-invasive decrypt IC firmware include playing around with the supply voltage and clock signal. Under-voltage and over-voltage IC firmware decrypt could be used to disable protection circuit or force a processor to do the wrong operation. For these reasons, some security processors have a voltage detection circuit, but this circuit cannot react to fast transients. Power and clock transients can also be used in some processors to affect the decoding and execution of individual instructions.