EM78159NAS EMC [ELAN Microelectronics Corp], EM78159NAS Datasheet - Page 30

• Manufacturer Part Number: EM78159NAS
• Description: 8-Bit Microcontroller with OTP ROM
• Manufacturer: EMC [ELAN Microelectronics Corp]

EM78P159N
8-Bit Microcontrollerwith OTP ROM
26 •
ERC (External RC oscillator mode); P55/OSCO act P55
ERC (External RC oscillator mode); P55/OSCO act OSCO
IRC (Internal RC oscillator mode) ; P55/OSCO act P55
IRC (Internal RC oscillator mode); P55/OSCO act OSCO
MCIRC (Manual calibration IRC mode); P55/OSCO act P55
MCIRC (Manual calibration IRC mode); P55/OSCO act OSCO
LXT (Low XTAL oscillator mode)
HXT (High XTAL oscillator mode) (default)
4.7 Oscillator
4.7.1 Oscillator Modes
The EM78P159N can be operated in four different oscillator modes, such as External
RC oscillator mode (ERC), Internal RC oscillator mode(IRC), High XTAL oscillator
mode (HXT), and Low XTAL oscillator mode (LXT). The desired mode can be selected
through programming of OSC2, OSC1, and OSC0 in the CODE option register. Table
below explains how these 4 oscillator modes are defined with OSC2, OSC1, and
OSC0.
The maximum operational frequency of crystal/resonator under different VDDs is as
listed below.
Oscillator Modes Defined by OSC
The transient point of system frequency between HXT and LXY is around 400 KHz.
Summary of Maximum Operating Speeds
Two cycles with two clocks
Conditions
Mode
(This specification is subject to change without further notice)
NOTE
Product Specification (V1.0) 03.10.2006
With Simulator
only
VDD
2.1
3.0
5.0
OSC2 OSC1 OSC0
0
0
0
0
1
1
1
1
Max Freq. (MHz)
20.0
4.0
8.0
0
0
1
1
0
0
1
1
0
1
0
1
1
0
1
0