EM78P153SP Ver la hoja de datos (PDF) - ELAN Microelectronics

Número de pieza

componentes Descripción

Fabricante

EM78P153SP

8-BIT MICRO-CONTROLLER

ELAN Microelectronics 

EM78P153S

OTP ROM

The sleep (power down) mode is attained by executing the “SLEP” instruction. While entering sleep

mode, WDT (if enabled) is cleared but keeps on running. The controller can be awakened by

(1) External reset input on /RESET pin,

(2) WDT time-out (if enabled), or

(3) Port 6 input status changes (if enabled).

The first two cases will cause the EM78P153S to reset. The T and P flags of R3 can be used to

determine the source of the reset (wake-up). The last case is considered the continuation of program

execution and the global interrupt ("ENI" or "DISI" being executed) decides whether or not the

controller branches to the interrupt vector following wake-up. If ENI is executed before SLEP, the

instruction will begin to execute from the address 008H after wake-up. If DISI is executed before

SLEP, the operation will restart from the instruction right next to SLEP after wake-up.

Only one of the Cases 2 and 3 can be enabled before entering the sleep mode. That is,

[a] if Port 6 input status changed interrupt is enabled before SLEP , WDT must be disabled. by

software. However, the WDT bit in the option register remains enabled. Hence, the EM78P153S can

be awakened only by Case 1 or 3.

[b] if WDT is enabled before SLEP, Port 6 Input Status Change Interrupt must be disabled. Hence, the

EM78P153S can be awakened only by Case 1 or 2. Refer to the section on interrupt.

If Port 6 Input Status Changed Interrupt is used to wake-up the EM78P153S (Case [a] above), the

following instructions must be executed before SLEP:

MOV

CONTW

WDTC

MOV

IOW

MOV

MOV

IOW

ENI (or DISI)

SLEP

A, @xxxx1110b ; Select WDT prescaler, prescaler must set over 1:1

A, @0xxxxxxxb

RE

R6, R6

A, @00000x1xb

RF

; Clear WDT and prescaler

; Disable WDT

; Read Port 6

; Enable Port 6 input change interrupt

; Enable (or disable) global interrupt

; Sleep

NOTE:

1. After waking up from the sleep mode, WDT is automatically enabled. The WDT enabled/disabled

operation after waking up from sleep mode should be appropriately defined in the software

2. To avoid a reset from occurring when the Port 6 Input Status Changed Interrupt enters into

interrupt vector or is used to wake-up the MCU, the WDT prescaler must be set above the 1:1

ratio.

This specification is subject to change without prior notice.

20

4. 1.2004 (V1.4)

Share Link: