SM39A16M1
8-Bit Micro-controller
16KB with ISP Flash
& 1K+256B RAM embedded
1.4 Clock Out Selection
The SM39A16M1 can Generator a clock out signal at P3.5， when user use Oscillator (XTAL1 as clock input) or
internal OSC as system clock. The CKCON [1:0] (at address 8Eh) can change any time.
CLKOUT: Clock output select.
CKCON [1:0]
Mode.
GPIO(default)
Fosc
00
01
10
11
Fosc/2
Fosc/4
It can be used when the system clock is the internal RC oscillator.
1.5 RESET
1.5.1 Hardware RESET function
SM39A16M1 provides Internal reset circuit inside，the Internal reset time can set by writer or ISP.
Internal Reset time
25ms (default)
200ms
100ms
50ms
16ms
8ms
4ms
1.5.2 Software RESET function
SM39A16M1 provides one software reset mechanism to reset whole chip. To perform a software reset, the firmware
must write three specific values 55h, AAh and 5Ah sequentially to the TAKEY register to enable the Software Reset
register (SWRES) write attribute. After SWRES register obtain the write authority, the firmware can write FFh to the
SWRES register. The hardware will decode a reset signal that “OR” with the other hardware reset. The SWRES
register is self-reset at the end of the software reset procedure.
Mnemonic
Description
Dir.
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RST
Software Reset function
LVRLP LVRLP
Reset status
register
Time Access
Key register
Software Reset
register
RSTS
TAKEY
SWRES
A1h
F7h
E7h
-
PDRF WDTF SWRF LVRF
PORF
00H
00H
00H
INTF
F
TAKEY [7:0]
SWRES [7:0]
FOSVOS TEL: 021-58998693
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M069 Ver C SM39A16M1 7/31/2013
- 16 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
