SyncMOS Technologies International, Inc.
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
SM89T16R1
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
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 bit set, ALE will be
active only during a MOVX instruction.
X32OUT: The 32.768KHz crystal output for RTC function.
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.
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.
Crystal 1:
Input to the inverting oscillator amplifier and input to the internal clock
generator circuits.
Crystal 2:
Output from the inverting oscillator amplifier.
8-Bits Micro-controller
With 64KB Flash ROM & 1KB RAM & Two UART & RTC & ADC & PWM embedded
ALE/X32OUT
30
27
33
#PSEN/X32IN
29
26
32
#EA
31
29
35
XTAL1
XTAL2
19
18
15
14
21
20
SFR Mapping
The special function register of SM89T16R1 fall into the following categories
C51 CORE register: ACC, B, DPL, DPH, PSW, SP
I/O ports: P0,P1, P2, P3, P4
Timer/Counter register: T2CON, T2MOD, TCON, TMOD, TH0, TH1, TH2, TL0, TL1, TL2, RCA2PL,
RCAP2H
The Second DPTR register: DPS, DPH1, DPL1
UART I/O register: SBUF, SCON
UART1 I/O register: SBUF1, SCON1
ADC register: ADCSC, ADCD, P2CON
Power and system control register: PCON, SCONF
Interrupt system register: IP, IE, IP1, IE1, IFR
Expand External Interrupt register: EIE, EIP, EXIF
RTC register: RTCC, RTCS
PWM output register: PWMC0, PWMC1, PWMD0, PWMD1, P1CON
PMM (Power Management) register: PMR
Specifications subject to change without notice contact your sales representatives for the most recent information.
5
Ver 2.1 SM89T16R1 08/2006
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
