Oscillation Circuit; Configuration Of Oscillation Circuit; Osc1 Oscillation Circuit - Epson S1C6P366 Technical Manual

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Oscillation Circuit)

4.3 Oscillation Circuit

4.3.1 Configuration of oscillation circuit

The S1C6P366 has two oscillation circuits (OSC1 and OSC3). OSC1 is a crystal oscillation circuit that
supplies the operating clock to the CPU and peripheral circuits. OSC3 is either a CR or a ceramic oscilla-
tion circuit. When processing with the S1C6P366 requires high-speed operation, the CPU operating clock
can be switched from OSC1 to OSC3 by the software.
Figure 4.3.1.1 is the block diagram of this oscillation system.

4.3.2 OSC1 oscillation circuit

The OSC1 oscillation circuit generates the main clock for the CPU and the peripheral circuits. The oscilla-
tor type is a crystal oscillation circuit and the oscillation frequency is 32.768 kHz (Typ.).
Figure 4.3.2.1 is the block diagram of the OSC1 oscillation circuit.
V
As shown in Figure 4.3.2.1, the crystal oscillation circuit can be configured simply by connecting the
crystal oscillator (X'tal) of 32.768 kHz (Typ.) between the OSC1 and OSC2 terminals and the trimmer
capacitor (C ) between the OSC1 and V
GX
22
OSC1
oscillation circuit
OSC3
oscillation circuit
Fig. 4.3.1.1 Oscillation system block diagram
C
GX
OSC1
OSC2
SS
Fig. 4.3.2.1 OSC1 oscillation circuit
terminals.
SS
Divider
To peripheral circuits
Clock
To CPU
switch
CPU clock selection signal
Oscillation circuit control signal
To CPU
(and peripheral circuits)
C
DX
EPSON
V
SS
S1C6P366 TECHNICAL MANUAL