Fujitsu MB90390 Series Hardware Manual page 189

■ Notes on Accessing the Low-power Consumption Mode Control Register (LPMCR) to
Enter the Standby Mode
●
To access the low-power consumption mode control register (LPMCR) with assembler language
To set the low-power consumption mode control register (LPMCR) to enter the standby mode, use the
instruction listed in Table 8.3-2.
The low-power consumption mode transition included in Table 8.3-2 must always be followed by an array
of instructions highlighted by a line below.
MOV
NOP
NOP
JMP
MOV
The device does not guarantee its operation after returning from the low-power consumption mode if you
place an array of instructions other than the one enclosed in the line.
●
To access the low-power consumption mode control register (LPMCR) with C language
To enter the standby mode using the low-power consumption mode control register (LPMCR), use one of
the following methods (1) to (3) to access the register.
(1)Specify the standby mode transition instruction as a function and insert two _wait_nop() built-in
functions after that instruction. If any interrupt other than the interrupt to return from the standby mode can
occur within the function, optimize the function during compilation to suppress the LINK and UNLINK
instructions from occurring.
(2)Define the standby mode transition instruction using _asm statements and insert two NOP and JMP
instructions after that instruction.
LPMCR, #H'XX ; the low-power mode transition instruction in Table 8.3-2
$+3 ; jump to next instruction
A, #H'10 ; any instruction
Example: Time-base timer mode transition function
Void enter_time-base(){
IO_LPMCR_byte = 0x10;
wait_nop();
wait_nop();
}
Example: Transition to sleep mode
_asm(" MOV I:_IO_LPMCR, #H'58");
_asm(" NOP");
_asm(" NOP");
_asm(" JMP $+3");
CHAPTER 8 LOW-POWER CONTROL CIRCUIT
/* Set LPMCR TMD bit to "0" */
/* Set LPMCR SLP bit to "1" */
/* Jump to next instruction */
161