em78p210n ELAN Microelectronics Corp, em78p210n Datasheet - Page 47

• Manufacturer Part Number: em78p210n
• Description: 8-bit Microcontroller With Otp Rom
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.2) 04.22.2008
(This specification is subject to change without further notice)
6.8 Oscillator
6.8.1 Oscillator Modes
The EM78P210N can be operated in six different oscillator modes, such as High Crystal
oscillator mode (HXT 1, 2), Low Crystal oscillator mode (LXT 1, 2), External RC oscillator
mode (ERC), and RC oscillator mode with Internal RC oscillator (IRC). Select one of
such modes by programming the OSC2, OCS1, and OSC0 in the Code Option register.
The Oscillator modes defined by OSC2, OCS1, and OSC0 are described below.
1
2
3
The maximum operating frequency limit of the crystal/resonator at different VDDs, are
as follows:
6.8.2
The EM78P210N can be driven by an external clock signal through the OSCO pin as
illustrated below.
ERC
ERC
IRC
IRC
LXT1
HXT1
LXT2
HXT2
In LXT1, LXT2, HXT1 and HXT2 modes; OSCI and OSCO are used as oscillator pins. These pins cannot
In ERC mode, OSCI is used as oscillator pin. OSCO/P52 is defined by code option Word 0 Bit 6 ~ Bit 4.
In IRC mode, P53 is normal I/O pin. OSCO/P52 is defined by code option Word 0 Bit 6 ~ Bit 4.
and should not be defined as normal I/O pins.
2
2
1
1
(Internal RC oscillator mode); P52/OSCO act as OSCO
(Internal RC oscillator mode); P52/OSCO act as P52
3
3
3
3
Conditions
(External RC oscillator mode); P52/OSCO act as P52
(External RC oscillator mode); P52/OSCO act as OSCO
Two clocks
(Frequency range of XT mode is 1MHz~100kHz)
(Frequency range of XT mode is 32kHz)
(Frequency range of XT mode is 16MHz~6MHz)
(Frequency range of XT mode is 6MHz~1MHz) (default)
Crystal Oscillator/Ceramic Resonators (Crystal)
Figure 6-13 External Clock Input Circuit
Oscillator Modes
OSCO
OSCI
VDD
2.1
3.0
4.5
8-Bit Microcontroller with OTP ROM
Max. Freq. (MHz)
Clock in
Clock out
16
Ext.
4
8
OSC2
0
0
0
0
1
1
1
1
OSC1
EM78P210N
0
0
1
1
0
0
1
1
OSC0
0
1
0
1
0
1
0
1
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