SM5M2 datasheet(19/28 Pages) SHARP

19 / 28 page

SM5M2

- 19 -

TRANSITION FROM THE OPERATION MODE TO THE

STANDBY MODE

The HALT instruction is executed to set the halt

mode and the STOP instruction is executed to set

the stop mode.

Since the interrupt is used to release from the

standby mode, the mode does not transfer to the

standby mode if any of the following conditions are

satisfied during execution of the STOP or HALT

instruction.

a) RE0 is set and the INTA level is High.

b) RE2 is set and the IFD flag is set.

If any of the conditions above is satisfied, the

mode does not transfer to the standby mode even

if the STOP or HALT instruction is executed and

the instruction at the address following that of the

STOP or HALT instruction is executed. Therefore,

place the JUMP instruction which specifies step 0

on page 3 to the location at the address following

that of the STOP or HALT instruction.

RELEASE FROM THE STANDBY MODE TO THE

OPERATION MODE

Release based on an interrupt request from the

INTA pin or divider overflow. However, the reset or

any port High in Port 1 is limited to a nonmaskable

interrupt request.

The program restarts from step 0 on page 3.

However, if the IME flag is set, the instruction at

step 0 on page 3 is executed and a subroutine

jump is performed to the interrupt processing

routine specified on page 2 according to the type

of interrupt.

Even if Low level input on INTA pin is removed

before 900 command cycles, the stop mode is

released.

However, the program will not jump to 20H page

(interrupt process routine).

Interrupt request flag IFA is not set : the program

continues at step 0 of page 3.

Interrupts

Interrupts originate from an INTA input or divider

overflow. The IFA and IFD flags become interrupt

request flags.

The interrupt block is composed of mask flags

(RE0, RE2), the IME flag and interrupt processing

circuit.

As shown in Fig. 11, resetting a mask flag enables

the interrupt request flag to be independently

masked. Thus, the mask flags can be used in a

program to establish the interrupt priority.

The

priority for interrupts generated simultaneously is

shown in Table 6.

During the standby mode, the contents of the RAM

and stack RAM are retained. The contents of the

flags, registers and output latches shown below are

also retained.

A release from the standby mode to the operation

mode is performed by a reset port input, an interrupt

from the nonmaskable INTA, any port High in Port 1,

and divider. A maskable interrupt request cannot

become a factor in releasing back to the operation

mode. The mask setting is performed with RE

CAUTION :

When all of P10 to P13 level are High, the SM5M2 is

performed to release the standby mode and enter normally

hardware reset operation. (Mask option)

FLAG

IFA flag

IFD flag

IME flag

C flag

P33 flag

ACC

X register

BM, BL register

SB register

OUTPUT LATCH REGISTER

P0 register

P1 register

P2 register

RC, RD, RE, RF

SM5M2 Datasheet(PDF) 19 Page - Sharp Corporation

SM5M2 Datasheet(HTML) 19 Page - Sharp Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Datasheet Download

Link URL