Krait (CPU)

Krait

Produced	2012
Designed by	Qualcomm
Common manufacturer(s)	Qualcomm
Max. CPU clock rate	1 GHz to 2.7 GHz
Instruction set	ARMv7-A, Thumb-2
Cores	2 or 4
L1 cache	16 KiB/16 KiB
L2 cache	1 MiB or 2 MiB
Predecessor	Scorpion
Successor	Kryo

Krait is an ARM-based central processing unit included in Qualcomm Snapdragon S4 and Snapdragon 400/600/800/801/805 (Krait 200, Krait 300, Krait 400 and Krait 450) System on chips. It was introduced in 2012 as a successor to the Scorpion CPU and although it has architectural similarities, Krait is not a Cortex-A15 core, but it was designed in-house.^[1]

Overview

• 11 stage integer pipeline with 3-way decode and 4-way out-of-order speculative issue superscalar execution
• Pipelined VFPv4^{[2][under discussion]} and 128-bit wide NEON (SIMD)
• 7 execution ports
• 4 KB + 4 KB direct mapped L0 cache
• 16 KB + 16 KB 4-way set associative L1 cache
• 1 MB 8-way set associative (dual-core) or 2 MB (quad-core) L2 cache
• Dual or quad-core configurations
• Performance (DMIPS/MHz):
  • Krait 200: 3.3 (28 nm LP)
  • Krait 300: 3.39^[3] (28 nm LP)
  • Krait 400: 3.39 (28 nm HPm)
  • Krait 450: 3.51 (28 nm HPm)

See also

• Scorpion (CPU)
• Kryo (microarchitecture)
• Comparison of ARMv7-A cores

References

1. Brian Klug; Anand Lal Shimpi (October 7, 2011). "Qualcomm's New Snapdragon S4: MSM8960 & Krait Architecture Explored". Anandtech. Retrieved 2013-07-28.
2. Brian Klug; Anand Lal Shimpi (February 21, 2012). "Qualcomm Snapdragon S4 (Krait) Performance Preview - 1.5 GHz MSM8960 MDP and Adreno 225 Benchmarks". Anandtech. Retrieved 2013-07-28.
3. Linley Gwennap (December 18, 2012). "Krait 300 Bumps Up Performance". Linley on Mobile. The Linley Group. Retrieved 2013-07-28.

External links

• Qualcomm's Snapdragon S4 Site.