|
The Apple A7 is a 64-bit system on a chip (SoC) designed by Apple Inc. It first appeared in the iPhone 5S, which was introduced on September 10, 2013. Apple states that it is up to twice as fast and has up to twice the graphics power compared to its predecessor, the Apple A6. While not the first 64-bit ARM CPU, it is the first to ship in a consumer smartphone or tablet computer. == Design == The A7 features an Apple-designed〔 64-bit 1.3–1.4 GHz ARMv8-A dual-core CPU,〔 called Cyclone.〔 The ARMv8-A instruction set doubles the number of registers of the A7 compared to the ARMv7 used in A6. It has 31 general purpose registers that are each 64-bits wide and 32 floating-point/NEON registers that are each 128-bits wide.〔 The A7 also integrates a graphics processing unit (GPU) which AnandTech believes to be a PowerVR G6430 in a four cluster configuration. The A7 has a per-core L1 cache of 64 KB for data and 64 KB for instructions, a L2 cache of 1 MB shared by both CPU cores,〔 and a 4 MB L3 cache that services the entire SoC.〔 The A7 includes a new image processor, a feature originally introduced in the A5, used for functionality related to the camera such as image stabilizing, color correction, and light balance. The A7 also includes an area called the "Secure Enclave" that stores and protects the data from the Touch ID fingerprint sensor on the iPhone 5S and iPad mini 3.〔 The security of the data in the Secure Enclave is probably enforced by ARM's TrustZone/SecurCore technology. In a change from the Apple A6, the A7 SoC no longer services the accelerometer, gyroscope and compass. In order to reduce power consumption, this functionality has been moved to the new M7 motion coprocessor which appears to be a separate ARM-based microcontroller from NXP Semiconductors. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Apple A7」の詳細全文を読む スポンサード リンク
|