SyncMOS Technologies Inc.

SM89S16R1

8-Bits Micro-controller

With 64KB Flash ROM & IKB RAM & RTC & ADC & PWM & PDWU embedded

Specifications subject to change without notice contact your sales representatives for the most recent information.

SM89S16R1 V1.0 JANUARY 2005

5

MNEMONIC

PDIP 40 pin

PQFP 44 Pin

PLCC 44 pin

Names and Functions

P3.0 – P3.7

10,11,12,13

14,15,16,17

5,7,8,9,

10,11,12,13

11, 13,14,15,

16,17,18,19

Port 3:

Port 3 is an 8-bits bidirectional I/O port with internal

pull-ups. Port 3 pins that have 1s written to them are pulled

high by the internal pull-ups and can be used as inputs. As

inputs, port 3 pins that are externally being pulled low will

source current because of the pull-ups. (See DC Electrical

Characteristics: IIL). Port 3 also serves the special features.

Port Pin

Alternative function

P3.0

RxD UART input

P3.1

TxD UART output

P3.2

#EX0 external interrupt 0

P3.3

#EX1 external interrupt 1

P3.4

T0: Timer 0 external input

P3.5

T1: Timer 1 external input

P3.6

#WR External data memory write strobe

P3.7

#RD External data memory read strobe

ALE/X32OUT

30

27

33

Address Latch Enable:

Output pulse for latching the low byte of the address during

an access to external memory. In normal operation, ALE is

emitted twice every machine cycle, and can be used for

external timing or clocking. Note that one ALE pulse is

skipped during each access to external data memory. Setting

SFR SCONF.0 can disable ALE. With this bits set, ALE will

be active only during a MOVX instruction.

X32OUT: The 32.768KHz crystal output for RTC function.

#PSEN/X32IN

29

26

32

Program Store Enable:

The read strobe to external program memory. When

executing code from the external program memory, #PSEN

is activated twice each machine cycle, except that two

#PSEN activations are skipped during each access to

external data memory. #PSEN is not activated during

fetches from internal program memory.

X32IN: The 32.768KHz crystal input for RTC

function.

#EA

31

29

35

External Access Enable:

#EA must be externally held low to enable the device to

fetch code from external program memory locations. If #EA

is held high, the device executes from internal program

memory.

X1

19

15

21

Crystal 1:

Input to the inverting oscillator amplifier and input to the

internal clock generator circuits.

X2

18

14

20

Crystal 2:

Output from the inverting oscillator amplifier.