Oscillator Types - Epson S1C33210 Technical Manual

III PERIPHERAL BLOCK: LOW-SPEED (OSC1) OSCILLATION CIRCUIT

Oscillator Types

In the low-speed (OSC1) oscillation circuit, either a crystal oscillation or an external clock input can be selected as the
type of oscillation circuit.
Figure 6.2 shows the structure of the low-speed (OSC1) oscillation circuit.
C
G1 OSC1
R X'tal1
f
OSC2
C
D1
V
SS
(1) Crystal oscillation circuit
When using a crystal oscillation for this circuit, connect a crystal resonator X'tal1 (32.768 kHz, Typ.) and feedback
resistor (Rf) between the OSC1 and OSC2 pins, and two capacitors (C
the OSC2 pin and V , respectively.
SS
When an external clock source is used, leave the OSC2 pin open and input a square-wave clock to the OSC1 pin.
If the low-speed (OSC1) oscillation circuit is not used, connect the OSC1 pin to V
The oscillation frequency is 32.768 kHz (Typ.). Use a crystal resonator or external clock that oscillates at this
frequency. No other frequency can be used for clock applications.
For details on oscillation characteristics and the external clock input characteristics, refer to "Electrical
Characteristics".
B-III-6-2
f
OSC1
Oscillation circuit
control signal
OSC1
OSC2
V
SS
(3) When not used
Figure 6.2 Low-Speed (OSC1) Oscillation Circuit
EPSON
OSC1
V
DD
V
SS
External
clock
N.C.
OSC2
(2) External clock input
Low level
Oscillation circuit
control signal
, C ) between the OSC1 pin and V
G1 D1
and leave the OSC2 pin open.
SS
f
OSC1
Oscillation circuit
control signal
and
SS
S1C33210 FUNCTION PART