Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 6 Clock Generation Circuit
FEUL620Q504 6–17
6.3.2 High-Speed Clock
For the high-speed clock generation circuit, the built-in RC oscillation mode, the crystal/ceramic oscillation mode,
or the external clock input mode can be selected.
6.3.2.1 High-Speed Built-in RC Oscillation Mode
Figure 6-9 shows the high-speed clock generation circuit configuration in the built-in RC oscillation mode.
When the RC oscillation clock is counted to 512, the high-speed oscillation clock (OSCLK) starts to be supplied.
Figure 6-9 Circuit Configuration in the Built-In RC Oscillation Mode
6.3.2.2 High-Speed Crystal/Ceramic Oscillation Mode
In crystal/ceramic oscillation mode, both the P10/OSC0 pin and the P11/OSC1 pin are used for crystal/ceramic
oscillation.
In crystal/ceramic oscillation mode, a crystal or a ceramic oscillator is externally connected to the P10/OSC0 and
P11/OSC1 pins. If the high-speed oscillation clock pulse count reaches 4096 after oscillation enable, the clock is
output to OSCLK (high-speed oscillation clock).
Figure 6-10 shows the circuit configuration in the crystal/ceramic oscillation mode.
Figure 6-10 Circuit Configuration in the Crystal/Ceramic Oscillation Mode
[Note]
•Install a crystal or a ceramic oscillator as close to the LSI as possible and make sure that signals causing
noise and power supply wiring are not near the crystal or the ceramic oscillator and their wiring.
•Note that oscillation may stop due to condensation.
P10/OSC0
16MHz
Crystal/ceramic oscillator
P11/OSC1
V
DD
STOP mode
High-speed
oscillation clock
R
FH
ENOSC (Enable oscillation)
V
SS
C
DH
C
GH
4096 counts
OSCLK (High-speed oscillation
clock)
V
DDL
RC oscillator
circuits
512 counts
ENOSC (Enable oscillation)
STOP mode