Renesas M32R-FPU Manuel d'utilisateur télécharger pdf (Page 106)

3-68

M32R-FPU Software Manual (Rev.1.01)

LOCKLOCK

load/store instruction

Load locked

[Mnemonic]

LOCK Rdest,@Rsrc

[Function]

Load locked

LOCK = 1, Rdest = *( int *) Rsrc;

[Description]

The contents of the word at the memory location specified by Rsrc are loaded into Rdest. The

condition bit (C) is unchanged.

This instruction sets the LOCK bit in addition to simple loading.

When the LOCK bit is 1, external bus master access is not accepted.

The LOCK bit is cleared by executing the UNLOCK instruction.

The LOCK bit is located in the CPU and operates based on the LOCK and UNLOCK instruc-

tions. The user cannot directly read or write to this bit.

The LOCK bit is internal to the CPU and is the control bit for receiving all bus right requests

from circuits other than the CPU.

Refer to the Users Manual for non-CPU bus right requests, as the handling differs according to

the type of MCU.

[EIT occurrence]

Address exception (AE)

[Encoding]

dest0010 LOCK Rdest,@Rsrcsrc1101

INSTRUCTIONS

3.2 Instruction description

1 2 ... 101 102 103 104 105 106 107 108 109 110 111 ... 193 194

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Renesas M32R-FPU Manuel d'utilisateur Page 106