We can restore avr controller ATTINY24 encrypted heximal, please view the avr controller ATTINY24 features for your reference:
If the code protection bit has not been encrypted HEX, the on-chip encrypted heximal memory can be read out for verification purposes.
The first 64 locations and the last location (Reset vector) can be read, regardless of the code protection bit setting.
Four memory locations are designated as ID locations where the user can store checksum or other code identification numbers. These locations are not accessible during normal execution, but are readable and writable during Restore AVR Controller ATtiny24 Encrypted Heximal.
Use only the lower 4 bits of the ID locations and always encrypted heximal the upper 8 bits as ‘0’s. The ATTINY24 microcontrollers can be serially encrypted heximalmed while in the end application circuit.
This is simply done with two lines for clock and data, and three other lines for power, ground and the encrypted heximalming voltage. This allows customers to manufacture boards with unencrypted heximalmed devices and then encrypted heximal the microcontroller just before shipping the product.
This also allows the most recent firmware or a custom firmware, to be encrypted heximalmed. The devices are placed into a encrypted heximal/Verify mode by holding the GP1 and GP0 pins low while raising the MCLR (VPP) pin from VIL to VIHH (see encrypted heximalming specification) if Restore AVR Controller ATtiny24 Encrypted Heximal.
GP1 becomes the encrypted heximalming clock and GP0 becomes the encrypted heximalming data. Both GP1 and GP0 are Schmitt Trigger inputs in this mode. After Reset, a 6-bit command is then supplied to the device.
Depending on the command, 16 bits of encrypted heximal data are then supplied to or from the device, depending if the command was a Load or a Read. For complete details of serial encrypted heximalming, please refer to the ATTINY24 encrypted heximalming Specifications after RECOVER MCU.