SM39A16M1
8-Bit Micro-controller
16KB with ISP Flash
& 1K+256B RAM embedded
Function Description
1. General Features
SM39A16M1 is an 8-bit micro-controller. All of its functions and the detailed meanings of SFR will be given in the
following sections.
1.1 Embedded Flash
The program can be loaded into the embedded 16KB Flash memory via its writer or In-System Programming (ISP).
The high-quality Flash has a 100K-write cycle life，suitable for re-programming and data recording as EEPROM.
1.2 IO Pads
The SM39A16M1 has Four I/O ports: Port 0, Port 1, Port 2 and Port 3. Ports 0, 1 are 8-bit ports and Port 2, 3 are 7-bit
ports. These are: quasi-bidirectional (standard 8051 port outputs), push-pull, open drain, and input-only. As description
in section 5.
All the pads for P0、P1、P2 and P3 are with slew rate to reduce EMI. The IO pads can withstand 4KV ESD in human
body mode guaranteeing the SM39A16M1‟s quality in high electro-static environments.
The RESET Pin can define as General I/O P3.4 when user use Internal RESET.
The XTAL2 and XTAL1 can define as P3.5 and P3.6 by writer or ISP，when user use internal OSC as system clock；
when user use external OSC as system clock and input into XTAL1，Only XTAL2 can be defined as P3.5.
1.3 Instruction timing Selection
The conventional 52-series MCUs are 12T, i.e., 12 oscillator clocks per machine cycle. SM39A16M1 is a 1T to 8T
MCU, i.e., its machine cycle is one-clock to eight-clock. In the other words, it can execute one instruction within one
clock to only eight clocks.
Mnemonic: CKCON
Address: 8Eh
7
-
6
5
4
3
-
2
-
1
0
Reset
10H
ITS[2:0]
CLKOUT[1:0]
ITS: Instruction timing select.
ITS [2:0]
000
Instruction timing
1T mode
001
010
2T mode (default)
3T mode
011
4T mode
100
5T mode
101
6T mode
110
7T mode
111
8T mode
The default is in 2T mode, and it can be changed to another Instruction timing mode if CKCON [6:4] (at address 8Eh) is
change any time. Not every instruction can be executed with one machine cycle. The exact machine cycle number for
all the instructions are given in the next section.
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M069
Ver C SM39A16M1 7/31/2013
- 15 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
