18.7.18 PLL1 Reference Divider
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | PLL1REFDIV |
| Offset: | 0x5C |
| Reset: | 0x00000000 |
| Property: | PAC Write-Protection, Enable-Protected |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| Access | |||||||||
| Reset |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| Access | |||||||||
| Reset |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| Access | |||||||||
| Reset |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| REFDIV[5:0] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | |||
Bits 5:0 – REFDIV[5:0] PLL1 Reference Division Factor
This field determines the division factor of the PLL1 input reference frequency. Writing to the REFDIV bits will cause lock to be lost. REFDIV value must be in the range of 1 ≤ REFDIV ≤ 63.
The frequency after the reference divider (FPFD) is given by the formula:
FPFD = FCKR / REFDIV (i.e., FPFD must always be between 4 MHz to 48 MHz.