Renesas M32R-FPU User Manual

3

3-68

M32R-FPU Software Manual (Rev.1.01)

load/store instruction

Load locked

LOCK = 1,  Rdest = *( int *) Rsrc;

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.

Address exception (AE)

INSTRUCTIONS

3.2 Instruction description