Epson S1C17M20 Technical Manual page 32

(2) CLGOSC1.OSC1BUP bit = 1 (startup boosting operation enabled)
Oscillator circuit enable
(CLGOSC.OSC1EN)
Oscillation inverter
Oscillation waveform
Figure 2.3.4.2 Operation Example when the OSC1 Crystal Oscillation Startup Control Circuit is Used
Oscillation start procedure for the IOSC oscillator circuit
Follow the procedure shown below to start oscillation of the IOSC oscillator circuit.
1. Write 1 to the CLGINTF.IOSCSTAIF bit. (Clear interrupt flag)
2. Write 1 to the CLGINTE.IOSCSTAIE bit. (Enable interrupt)
3. Write 1 to the CLGOSC.IOSCEN bit.
4. IOSCCLK can be used if the CLGINTF.IOSCSTAIF bit = 1 after an interrupt occurs.
Oscillation start procedure for the OSC1 oscillator circuit
Follow the procedure shown below to start oscillation of the OSC1 oscillator circuit.
1. Write 1 to the CLGINTF.OSC1STAIF bit.
2. Write 1 to the CLGINTE.OSC1STAIE bit.
3. Write 0x0096 to the MSCPROT.PROT[15:0] bits. (Remove system protection)
4. Configure the following CLGOSC1 register bits:
- CLGOSC1.OSC1SELCR bit
- CLGOSC1.OSC1WT[1:0] bits
In addition to the above, configure the following bits when using the crystal oscillator:
- CLGOSC1.INV1N[1:0] bits
- CLGOSC1.CGI1[2:0] bits
- CLGOSC1.INV1B[1:0] bits
- CLGOSC1.OSC1BUP bit
5. Write a value other than 0x0096 to the MSCPROT.PROT[15:0] bits. (Set system protection)
6. Write 1 to the CLGOSC.OSC1EN bit.
7. OSC1CLK can be used if the CLGINTF.OSC1STAIF bit = 1 after an interrupt occurs.
The setting values of the CLGOSC1.INV1N[1:0], CLGOSC1.CGI1[2:0], CLGOSC1.OSC1WT[1:0], and
CLGOSC1.INV1B[1:0] bits should be determined after performing evaluation using the populated circuit board.
Note: Make sure the CLGOSC.OSC1EN bit is set to 0 (while the OSC3 oscillation is halted) when
switching the oscillator within two types.
Oscillation start procedure for the OSC3 oscillator circuit
Follow the procedure shown below to start oscillation of the OSC3 oscillator circuit.
1. Write 1 to the CLGINTF.OSC3STAIF bit.
2. Write 1 to the CLGINTE.OSC3STAIE bit.
3. Write 0x0096 to the MSCPROT.PROT[15:0] bits. (Remove system protection)
4. Configure the following CLGOSC3 register bits:
- CLGOSC3.OSC3MD bit
- CLGOSC3.OSC3WT[2:0] bits
In addition to the above, configure the following bits when using the crystal/ceramic oscillator:
- CLGOSC3.OSC3INV[1:0] bits
Configure the following bits when using the internal oscillator:
- CLGOSC3.OSC3FQ[1:0] bits
S1C17M20/M21/M22/M23/M24/M25
TECHNICAL MANUAL (Rev. 1.0)
INV1B[1:0] setting gain
Startup boosting
operation
(Start oscillation)
(Clear interrupt flag)
(Enable interrupt)
(Select oscillator type)
(Set oscillation stabilization waiting time)
(Set oscillation inverter gain)
(Set internal gate capacitor)
(Set oscillation inverter gain for startup boosting period)
(Enable/disable oscillation startup control circuit)
(Start oscillation)
(Clear interrupt flag)
(Enable interrupt)
(Select oscillator type)
(Set oscillation stabilization waiting time)
(Set oscillation inverter gain)
(Select oscillation frequency)
Seiko Epson Corporation
2 POWER SUPPLY, RESET, AND CLOCKS
INV1N[1:0] setting gain
Normal operation
2-9