SM39R4051 Datasheet, PDF (9/47 Pages) SyncMOS Technologies,Inc – One serial peripheral interfaces in full duplex mode

SM39R4051/SM39R2051
8-Bit Micro-controller
4KB/2KB with ISP Flash
& 256B RAM embedded
Function Description
1. General Features
SM39R4051 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 4KB/2KB 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 SM39R4051 has three I/O ports: Port 1, Port 3 and Port 4. Ports 1, 3 are 8-bit ports and Port 4 is a 2-bit port. These
are: quasi-bidirectional (standard 8051 port outputs), push-pull, open drain, and input-only. As description in section 5。
At 20L Package (DIP/SOP)，the Int0、Int1、T0、T0 signal can be configured to other I/O as below：
Signal Default Option1 Option2 Option3
#INT0 6(P3.2) 2(P3.0) 15(P1.3) 16(P1.4)
#INT1 7(P3.3) 3(P3.1) 14(P1.2) 17(P1.5)
T0
8(P3.4) 14(P1.2) 16(P1.4) 2(P3.0)
T1
9(P3.5) 15(P1.3) 17(P1.5) 3(P3.1)
The RESET Pin Can Be configured as I/O port P3.6，when user use on-chip hardware RESET mechanism。
The XTAL2 and XTAL1 can be configured as I/O port by ICP or in ISP mode，when user use external OSC or on-chip RC
Oscillator is set to main system clock source，show as below：
20L package
Xtal1
Xtal2
External OSC
Xtal1
P4.0
Internal OSC
P4.1
P4.0
All the pins on P1、P3 and P4 are with slew rate adjustment to reduce EMI. The other way to reduce EMI is to disable the
ALE output if unused. This is selected by its SFR. The IO pads can withstand 4KV ESD in human body mode
guaranteeing the SM39R4051’s quality in high electro-static environments.
1.3. Instruction timing Selection
The conventional 52-series MCUs are 12T, i.e., 12 oscillator clocks per machine cycle. SM39R4051 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
-
ITS
-
-
-
-
10H
ITS: Instruction timing select.
ITS [6:4]
Instruction timing
000
1T mode
001
2T mode (default)
010
3T mode
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M055
9
Ver.E SM39R4051 09/2011