conditional instructions of
- By carefully examining the layout of the ARM1 processor, it can be reverse engineered. This article describes the interesting circuit used for conditional instructions: this circuit is marked in red on the die photo below. Unlike most processors, the ARM executes every instruction conditionally. Each instruction specifies a condition and is only executed if the condition is satisfied. For every instruction, the condition circuit reads the condition from the instruction register (blue), evaluates the condition flags (purple), and informs the control logic (yellow) if the instruction should be executed or skipped.
- Dimetrodon (Wikipedia)
Dimetrodon (/daɪˈmiːtrəˌdɒn/ or /daɪˈmɛtrəˌdɒn/; lit. ’two measures of teeth’) is an extinct genus of non-mammalian synapsid belonging to the family Sphenacodontidae that lived during the Cisuralian age of the Early [Permian](Permian period, around 295–272 million years ago. With most species measuring 1.7–4.6 m (5.6–15.1 ft) long and weighing 28–250 kg (62–551 lb), the most prominent feature of Dimetrodon is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It was an obligate quadruped (it could only walk on four legs) and had a tall, curved skull with large teeth of different sizes set along the jaws.