Abstract: Cryptographic hashing circuitry such as mining circuitry used to mine digital currency may be formed on an integrated circuit. The hashing circuitry may include sequential rounds of register and logic circuitry that perform operations of a cryptographic protocol. A final hash output from the hashing circuitry may be checked using a difficulty comparison circuit to determine whether the hash output satisfies predetermined difficulty criteria. The difficulty comparison circuit may be configured as a hardwired comparison circuit having logic gates for checking only a subset of bits in the hash output. The comparison circuit may be adapted to change the number of bits that is checked based on a target number of bits for comparison set by the Bitcoin protocol. Candidate solutions found using the hardwired comparison circuit may then be fed to a host controller that checks the entire hash output to determine whether the candidate solution is valid.

Abstract: An integrated circuit may be provided with cryptocurrency mining capabilities. The integrated circuit may include control circuitry and a number of processing cores that complete a Secure Hash Algorithm 256 (SHA-256) function in parallel. Logic circuitry may be shared between multiple processing cores. Each processing core may perform sequential rounds of cryptographic hashing operations based on a hash input and message word inputs. The control circuitry may control the processing cores to complete the SHA-256 function over different search spaces. The shared logic circuitry may perform a subset of the sequential rounds for multiple processing cores. If desired, the shared logic circuitry may generate message word inputs for some of the sequential rounds across multiple processing cores. By sharing logic circuitry across cores, chip area consumption and power efficiency may be improved relative to scenarios where the cores are formed using only dedicated logic.

Abstract: Digital systems formed on integrated circuits may include sequential logic circuitry. The sequential logic circuitry may form at least part of a finite state machine that records different logical states. The sequential logic circuitry may include a first latching circuit and a second latching circuit that each latch bits onto their respective outputs when clocked at different levels. The first latching circuit may output a first bit. Combinational logic circuitry may be distributed on both sides of the first latching circuit such that a combinational logic circuit interposed between the first and second latching circuits generates a second bit based on at least the first bit. The first and second bits may record one of two possible finite logical states of the sequential logic circuitry. By distributing combinational logic circuitry on two sides of a given latching circuit, dynamic power consumption by the sequential logic circuitry may be optimized.

Abstract: Cryptographic hashing circuitry such as mining circuitry used to mine digital currency may be formed on an integrated circuit. The hashing circuitry may include sequential rounds of register and logic circuitry that perform operations of a cryptographic protocol. A final hash value output by the hashing circuitry may include hash values stored at previous rounds of the cryptographic hashing circuitry. The hashing circuitry may be formed with only two registers per round, thereby optimizing chip area consumption. The hashing circuitry may perform sequential rounds of cryptographic hashing based on an initial hash value and multiple message words. One or more message registers may store the message words. Control circuitry may selectively route the message words from the message register to the hashing circuitry using pointers. If desired, the message registers may be replaced by one or more arrays of memory elements read using row and column pointers.

Abstract: Circuit design equipment may design logic for a circuit. The design equipment may discover optimized design constraints and an optimized clock signal frequency for the circuit. The design equipment may output the discovered optimized clock signal frequency and design constraints to circuit fabrication equipment for fabricating the corresponding circuit. The design equipment may discover the optimized clock signal frequency and design constraints by populating a cost function with different clock signal frequencies and different design constraint values. The cost function may be, for example, a multi-dimensional surface. The design equipment may identify a global minimum of the cost function and may identify the clock signal frequency and design constraint values that correspond to the global minimum as the optimized clock frequency and optimized design constraints to provide to circuit fabrication equipment.

Abstract: Mining circuitry may be used to mine digital currency such as bitcoins by computing solutions to a cryptographic puzzle. Successful computation of a solution to the cryptographic puzzle may provide a reward of the digital currency. The mining circuitry may partition the mined reward between a first digital wallet and a second digital wallet. The first digital wallet may be user-provided, whereas the second digital wallet may be hardcoded into the dedicated mining circuitry. The mining circuitry may include control circuitry and multiple processing core circuits. The control circuitry may control the processing cores to solve the cryptographic puzzle via exhaustive search over possible inputs to the cryptographic puzzle.