SM39R08A5
8-Bit Micro-controller
with 8KB Flash
& 256B RAM embedded
1.5.4. Time Access Key register (TAKEY)
Mnemonic: TAKEY
7
6
5
4
3
TAKEY [7:0]
2
1
Address: F7H
0
Reset
00H
Software reset register (SWRES) is read-only by default; software must write three specific values
55h, AAh and 5Ah sequentially to the TAKEY register to enable the SWRES register write attribute. That
is:
MOV TAKEY, #55h
MOV TAKEY, #0AAh
MOV TAKEY, #5Ah
1.5.5. Software Reset register (SWRES)
Mnemonic: SWRES
7
6
5
4
3
SWRES [7:0]
2
1
Address: E7H
0
Reset
00H
SWRES [7:0]: Software reset register bit. These 8-bit is self-reset at the end of the reset procedure.
SWRES [7:0] = FFh, software reset.
SWRES [7:0] = 00h ~ FEh, MCU no action.
1.5.6. Example of software reset
MOV TAKEY, #55h
MOV TAKEY, #0AAh
MOV TAKEY, #5Ah ; enable SWRES write attribute
MOV SWRES, #0FFh ; software reset MCU
1.6. Clocks
The default clock is the 22.1184MHz Internal OSC. This clock is used during the initialization stage. The major work of the
initialization stage is to determine the clock source used in normal operation.
The internal clock sources are from the internal OSC with difference frequency division as given in Table 1-1, the clock
source can set by writer or ICP.
Table 1-1: Selection of clock source
Clock source
22.1184MHz from internal OSC
11.0592MHz from internal OSC
5.5296MHz from internal OSC
2.7648MHz from internal OSC
1.3824MHz from internal OSC
There may be having a little variance in the frequency from the internal OSC. The max variance as giving in Table 1-1
Table 1-1: Temperature with variance
Temperature Max Variance
25℃
±2%
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M067
Ver B SM39R08A5 04/22/2013
- 12 -
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
