em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 169

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.0) 05.05.2010
(This specification is subject to change without further notice)
6.19.2 Code Option Register (Word 1)
6.19.2.1 EM78F644/642/641/544/542/541N Code Option Word 1
Bit 12 (COBS0): IRC mode selection bit
Bit 11 (TCEN): TCC enable bit
Bit 10:
Bit 9:
Bit 8 ~ Bit 4 (C4 ~ C0): Internal RC mode calibration bits.
Bit 3 ~ Bit 2 (RCM1 ~ RCM0): RC mode selection bits
Bit 1 ~ Bit 0 (LVR1 ~ LVR0): Low Voltage Reset Enable bits
COBS0
Bit 12 Bit 11 Bit 10 Bit 9
TCEN
“0”
0: Select IRC frequency from code option (default)
1: Select IRC frequency from register
0: P77/TCC is set as P77 (default)
1: P77/TCC is set as TCC.
Not used, set to “0” all the time.
Not used, set to “1” all the time.
C4 ~ C0 must be set to “0” only (auto-calibration).
LVR1, LVR0=“0, 0”: LVR is disabled. The IC power-on reset is
LVR1, LVR0=“0, 1”: If Vdd < 2.7V, the IC will reset.
LVR1, LVR0=“1, 0”: If Vdd < 3.5V, the IC will reset.
LVR1, LVR0=“1, 1”: If Vdd < 4.0V, the IC will reset.
“1”
LVR1
The frequency 455kHz is NOT available from EM78F641/541N
RCM 1
0
0
1
1
Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0
0
1
1
C4
TCEN must be set to”0” in EM78F641/541N
EM78F648/644/642/641/548/544/542/541N
C3
2.0~2.1V (default).
Word 1
LVR0
C2
0
1
0
1
RCM 0
C1
NOTE
NOTE
0
1
0
1
Reset Level
C0
2.7V
3.5V
4.0V
NA
RCM1 RCM0 LVR1 LVR0
8-Bit Microcontroller
Frequency (MHz)
4 (default)
Release Level
455kHz
16
8
2.9V
3.7V
4.2V
NA
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