We can Read Out Code of Protected MCU dsPIC30F1010, please view the MCU dsPIC30F1010 features for your reference:
If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag bit is se t (eighth bit) and on the falling edge of the ninth bit (ACK bit), the SSPIF interrupt flag bit is set. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF. The value can be used to determine if the address was device specific or a general call address.
In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when the GCEN bit is set, while the slave is configured in 10-bit Address mode, then the second half of the address is not necessary, the UA bit will not be set and the slave will begin receiving data after the Acknowledge. Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware if the firmware of chip can be read.
Master mode of operation is supported by interrupt generation on the detection of the Start and Stop conditions. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit is set, or the bus is Idle, with both the S and P bits clear. In Firmware Controlled Master mode, user code conducts all I 2C bus operations based on Start and Stop bit conditions. Once Master mode is enabled, the user has six options to crack MCU.
Assert a Start condition on SDA and SCL.
Assert a Repeated Start condition on SDA and SCL.
Write to the SSPBUF register initiating transmission of data/address.
Configure the I2C port to receive data.
Generate an Acknowledge condition at the end of a received byte of data.
Generate a Stop condition on SDA and SCL.