ST20C2 datasheet(66/212 Pages) STMICROELECTRONICS

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devmove

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devmove

device move

Code: 62 F4

Description: Perform a device copy between memory or memory-mapped devices.

Copies Areg bytes to address Breg from address Creg. Only the minimum number of

reads and writes required to copy the data will be performed. Each read will be to a

strictly higher (more positive) address than the one before and each write will be to a

strictly higher byte address than the one before. There is no guarantee of the relative

ordering of read and write cycles, except that a write cannot occur until the

corresponding read has been performed. The memory accesses performed by this

instruction are guaranteed to be correctly sequenced with respect to other device-

access instructions. Also the instruction is guaranteed to be executed after all normal

memory access instructions that appear before it in the code sequence, and before all

normal memory accesses that appear after it.

Definition:

if (

source and destination overlap)

Undefined effect

else for i

= 0 .. (Areg

unsigned − 1)

byte

′[Breg + i] ← byte[Creg + i]

Areg

′← undefined

Breg

′← undefined

Creg

′← undefined

Error signals: none

Comments:

Secondar y instruction.

The effect of the instruction is undefined if the source and destination overlap.

Instruction is interruptible.

Devmove will not operate from or to peripheral addresses.

ST20C2 Datasheet(PDF) 66 Page - STMicroelectronics