32.22.8 PMC Clock Generator Main Oscillator Register
| Name: | CKGR_MOR |
| Offset: | 0x0020 |
| Reset: | 0x01000021 |
| Property: | Read/Write |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| XT32KFME | CFDEN | MOSCSEL | |||||||
| Access | R/W | R/W | R/W | ||||||
| Reset | 0 | 0 | 1 |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| KEY[7:0] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| MOSCXTST[7:0] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| ZERO | ONE | ZERO | MOSCRCEN | WAITMODE | MOSCXTBY | MOSCXTEN | |||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | ||
| Reset | 0 | 1 | 0 | 0 | 0 | 0 | 1 |
Bit 26 – XT32KFME 32.768 kHz Crystal Oscillator Frequency Monitoring Enable
| Value | Description |
|---|---|
| 0 | The 32.768 kHz crystal oscillator frequency monitoring is disabled. |
| 1 | The 32.768 kHz crystal oscillator frequency monitoring is enabled. |
Bit 25 – CFDEN Clock Failure Detector Enable
| Value | Description |
|---|---|
| 0 |
The clock failure detector is disabled. |
| 1 |
The clock failure detector is enabled. |
Bit 24 – MOSCSEL Main Clock Oscillator Selection
| Value | Description |
|---|---|
| 0 | The 12 MHz RC oscillator is selected. |
| 1 | The 8 to 24 MHz crystal oscillator is selected. |
Bits 23:16 – KEY[7:0] Password
| Value | Name | Description |
|---|---|---|
| 0x37 | PASSWD | Writing any other value in this field aborts the write operation. |
Bits 15:8 – MOSCXTST[7:0] 8 to 24 MHz Crystal Oscillator Start-up Time
Specifies the number of Slow clock cycles multiplied by 8 for the crystal oscillator start-up time.
Bit 5 – ONE Must Be Set to 1
Bit 5 must always be set to 1.
Bits 4, 6 – ZERO Must Be Set to 0
Bit 3 – MOSCRCEN 12 MHz RC Oscillator Enable
When MOSCRCEN is set, the MOSCRCS flag is set once the RC oscillator start-up time is achieved.
| Value | Description |
|---|---|
| 0 |
The 12 MHz RC oscillator is disabled. |
| 1 |
The 12 MHz RC oscillator is enabled. |
Bit 2 – WAITMODE ULP1 Mode Command (Write-only)
| Value | Description |
|---|---|
| 0 |
No effect. |
| 1 |
Puts the device in ULP1 mode. |
Bit 1 – MOSCXTBY 8 to 24 MHz Crystal Oscillator Bypass
When MOSCXTBY is set, the MOSCXTS flag in PMC_SR is automatically set.
Clearing MOSCXTEN and MOSCXTBY bits resets the MOSCXTS flag.
When Main Oscillator Bypass is disabled (MOSCXTBY = 0), the MOSCXTS flag must be read as 0 in PMC_SR prior to enabling the main crystal oscillator (MOSCXTEN = 1).
| Value | Description |
|---|---|
| 0 | No effect. |
| 1 | The 8 to 24 MHz crystal oscillator is bypassed. MOSCXTEN must be cleared. An external clock must be connected on XIN. |
Bit 0 – MOSCXTEN 8 to 24 MHz Crystal Oscillator Enable
A crystal must be connected between XIN and XOUT.
When MOSCXTEN is set, the MOSCXTS flag is set once the crystal oscillator start-up time is achieved.
| Value | Description |
|---|---|
| 0 | The 8 to 24 MHz crystal oscillator is disabled. |
| 1 | The 8 to 24 MHz crystal oscillator is enabled. MOSCXTBY must be cleared. |