EM78P510N
8-Bit Microcontrollers
6.6 Oscillator
6.6.1 Oscillator Modes
The EM78P510N can be operated in the three different oscillator modes for the main
oscillator (R-OSCI, OSCO), namely, RC oscillator with external resistor and Internal
capacitor mode (IC), crystal oscillator mode, and PLL operation mode. User can select
one of those three modes by programming FMMD1 and FMMD0 in the Code Option
register, the sub-oscillator can be operated in crystal mode and ERIC mode. Table 3
shows these three modes are defined.
Table 3 Oscillator Modes Defined by FSMD, FMMD1, FMMD0.
FSMD
FMMD1
FMMD0
Main Clock
RC type (ERIC)
Crystal type
PLL type
Sub-clock
RC type (ERIC)
RC type (ERIC)
RC type (ERIC)
RC type (ERIC)
Crystal type
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
PLL type
RC type (ERIC)
Crystal type
PLL type
Crystal type
Crystal type
Crystal
None
Table 4 Summary of Maximum Operating Speeds
Conditions
VDD
2.0
Fxt max.(MHz)
4
8
Two clocks
3.0
5.0
16
6.6.2 Crystal Oscillator/Ceramic Resonators (Crystal)
EM78P510N can be driven by an external clock signal through the OSCO pin as shown
in Fig.6-6 below.
Figure 6-6 External Clock Input Circuit
52 •
Product Specification (V0.9) 09.12.2006
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
