SM89T16R1 Datasheet, PDF (27/34 Pages) SyncMOS Technologies,Inc – 8-Bits Micro-controller With 64KB Flash ROM & IKB RAM & Two UART & RTC & ADC & PWM embedded

SyncMOS Technologies Inc.
SM89T16R1
8-Bits Micro-controller
With 64KB Flash ROM & IKB RAM & Two UART & RTC & ADC & PWM embedded
The Power Down Wake Up (PDWU) function
The device can be put into Power Down mode by writing 1 to bit PCON.1. The instruction that does this will be the
last instruction to be executed before the device goes into Power Down mode. In the Power Down mode, all the
clocks are stopped and the device comes to a halt. All activity is completely stopped and the power consumption is
reduced to the lowest possible value. In this state the ALE and PSEN pins are pulled low. The port pins output the
values held by their respective SFRs.
The SM89T16R1 will exit the Power Down mode with a reset or by a RTC (Real Time Clock) interrupt or by an
external interrupts pin enabled as level detects.
1. An external reset can be used to exit the Power Down state. The high on RST pin terminates the Power Down mode,
and restarts the clock. The program execution will restart from 0000H.
2. An external interrupt pin and RTC interrupt can be used to exit the Power Down state when the external interrupt or
RTC interrupt actives and provided the corresponding interrupt is enabled, while the global enable (EA) bit is set and
the external input has been set to a level detect mode or RTC interrupt set. If these conditions are met, then the low
level on the external pin or RTC interrupt re-starts the oscillator. Then device executes the interrupt service routine for
the corresponding external interrupt or RTC interrupt. After the interrupt service routine is completed, the program
execution returns to the instruction after the one that put the device into Power Down mode and continues from there.
The status of external pins during Idle and Power Down:
Mode
Idle
Idle
Power Down
Power Down
Program
Memory
Internal
External
Internal
External
ALE
1
1
0
0
/PSEN PORT0 PORT1 PORT2 PORT3 PORT4
1
Data
Data
Data
Data
Data
1
Float
Data Address Data
Data
0
Data
Data
Data
Data
Data
0
Float
Data
Data
Data
Data
PCON ($87H)
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
SMOD
SMOD0
PD
SMOD: This bit set to ‘1’ to make the UART baud-rate double.
SMOD0: This bit define the SCON.7 and SCON1.7 use as FE (FE1) or SM0 (SM0_1)
PD: When set to ‘1’, the MCU will into Power Down mode
IDLE: When set to ‘1’, the MCU will into IDLE mode
Bit0
IDLE
IE ($A8H)
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
EA
ET1
ET2
ES0
ET1
EX1
ET0
EX0
EA: When set to ‘1’, enable interrupt global.
ET1: When set to ‘1’, enable Timer1 interrupt.
ET2: When set to ‘1’, enable Timer2 interrupt.
ES0: When set to ‘1’, enable UART interrupt.
ET1: When set to ‘1’, enable Timer1 interrupt.
EX1: When set to ‘1’, enable external interrupt 1.
ET0: When set to ‘1’, enable Timer0 interrupt.
EX0: When set to ‘1’, enable external interrupt 0.
IP ($B8H)
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
PT2
PS0
PT1
PX1
PT0
PX0
PT2: Timer2 interrupt priority.
PS0: UART interrupts priority.
Specifications subject to change without notice contact your sales representatives for the most recent information.
SM89T16R1 V1.0 JANUARY 2005
27