Input/Output Pins; Clock Sources - Epson S1C17W14 Technical Manual

2.3.2 Input/Output Pins

Table 2.3.2.1 lists the CLG pins.
Pin name I/O*
OSC1 A
OSC2 A
OSC3 A
OSC4 A
EXOSC I
FOUT O
If the port is shared with the CLG input/output function and other functions, the CLG function must be assigned to
the port. For more information, refer to the "I/O Ports" chapter.

2.3.3 Clock Sources

IOSC oscillator circuit
The IOSC oscillator circuit features a fast startup and no external parts are required for oscillating. Figure 2.3.3.1
shows the configuration of the IOSC oscillator circuit.
OSC1
OSC1CLK
oscillator
circuit
The IOSC oscillator circuit output clock IOSCCLK is used as SYSCLK at booting. The IOSC oscillator circuit
is equipped with an auto-trimming function that automatically adjusts the frequency. This helps reduce fre-
quency deviation due to unevenness in manufacturing quality, temperature, and changes in voltage. For more
information on the auto-trimming function and the oscillation characteristics, refer to "IOSC oscillation auto-
trimming function" in this chapter and "IOSC oscillator circuit characteristics" in the "Electrical Characteris-
tics" chapter, respectively.
OSC1 oscillator circuit
The OSC1 oscillator circuit is a high-precision and low-power oscillator circuit that uses a 32.768 kHz crystal
resonator. Figure 2.3.3.2 shows the configuration of the OSC1 oscillator circuit.
S1C17W14/W16 TECHNICAL MANUAL
(Rev. 1.2)
Table 2.3.2.1 List of CLG Pins
Initial status*
– OSC1 oscillator circuit input
– OSC1 oscillator circuit output
– OSC3 oscillator circuit input
– OSC3 oscillator circuit output
I EXOSC clock input
O (L) FOUT clock output
IOSC oscillator circuit
IOSCEN
Clock
oscillator
Auto- IOSCSTAIE
trimming IOSCTEDIE
circuit
IOSCSTM
Figure 2.3.3.1 IOSC Oscillator Circuit Configuration
Seiko Epson Corporation
2 POWER SUPPLY, RESET, AND CLOCKS
Function
* Indicates the status when the pin is configured for CLG.
Oscillation
stabilization
waiting circuit
IOSCSTAIF
Interrupt
IOSCTEDIF
control circuit
IOSCCLK
Interrupt
controller
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