Abstract:
Techniques to securely boot up an electronics device (e.g., a cellular phone) from an external storage device are described. Secure data (e.g., a hash digest, a signature, a cryptographic key, and so on) is initially retrieved from a non-writable area of an external memory device (e.g., an one-time programmable (OTP) area of a NAND Flash device). A first program (e.g., a boot program) is retrieved from a writable or main area of the external memory device and authenticated based on the secure data. The first program is enabled for execution if authenticated. A second program may be retrieved from the main area of the external memory device and authenticated based on the secure data. The second program is enabled for execution if authenticated. Additional programs may be retrieved and authenticated. Each program may be authenticated using a secure hash function, a digital signature, and/or some other cryptographic technique.
Abstract:
Methods and systems for an in-system repair process that repairs or attempts to repair random bit failures in a memory device are provided. In some examples, an in-system repair process may select alternative steps depending on whether the failure is correctable or uncorrectable. In these examples, the process uses communications between a system on chip and the memory to fix the failures during normal operation.
Abstract:
A system and method of refreshing dynamic random access memory (DRAM) are disclosed. A device includes a DRAM, a bus, and a system-on-chip (SOC) coupled via the bus to the DRAM. The SOC is configured to refresh the DRAM at a particular refresh rate based on a temperature of the DRAM and based on calibration data determined based on one or more calibration tests performed while the SOC is coupled to the DRAM.
Abstract:
In a repair of a random access memory (RAM), an error information is received, a fail address of the RAM identified, and a one-time programming applied to a portion of the redundancy circuit while a content of the RAM is valid. The RAM is a dynamic access RAM (DRAM), a refresh burst is applied to the DRAM, followed by a non- refresh interval, and the one-time programming is performed during the non-refresh interval.