PM0056 datasheet(25/156 Pages) STMICROELECTRONICS

No. de pieza	PM0056

Descripción Electrónicos	This programming manual provides information

PDF	156 Pages

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Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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DocID15491 Rev 5

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PM0056

The Cortex-M3 processor

2.2.1

Memory regions, types and attributes

The memory map splits the memory map into regions. Each region has a defined memory

type, and some regions have additional memory attributes. The memory type and attributes

determine the behavior of accesses to the region.

The memory types are:

The different ordering requirements for Device and Strongly-ordered memory mean that the

memory system can buffer a write to Device memory, but must not buffer a write to Strongly-

ordered memory.

The additional memory attributes include:

Normal

The processor can re-order transactions for efficiency, or

perform speculative reads.

Device

The processor preserves transaction order relative to other

transactions to Device or Strongly-ordered memory.

Strongly-ordered

The processor preserves transaction order relative to all other

transactions.

Execute Never (XN)

Means the processor prevents instruction accesses. Any

attempt to fetch an instruction from an XN region causes a

memory management fault exception.

PM0056 Datasheet(PDF) 25 Page - STMicroelectronics