| 전자부품 데이터시트 검색엔진 |
|
WM8510GEDS/V 데이터시트(PDF) 54 Page - Wolfson Microelectronics plc |
|
|
|||||||||||||||||||||||||||||
WM8510GEDS/V 데이터시트(HTML) 54 Page - Wolfson Microelectronics plc |
|
54 / 81 page ![]() WM8510 Production Data w PD Rev 4.1 December 2006 54 The PLL frequency ratio R = f2/f1 (see Figure 31) can be set using the register bits PLLK and PLLN: PLLN = int R PLLK = int (2 24 (R-PLLN)) EXAMPLE: MCLK=12MHz, required clock = 12.288MHz. R should be chosen to ensure 5 < PLLN < 13. There is a fixed divide by 4 in the PLL and a selectable divide by N after the PLL which should be set to divide by 2 to meet this requirement. Enabling the divide by 2 sets the required f2 = 4 x 2 x 12.288MHz = 98.304MHz. R = 98.304 / 12 = 8.192 PLLN = int R = 8 k = int ( 2 24 x (8.192 – 8)) = 3221225 = 3126E9h REGISTER ADDRESS BIT LABEL DEFAULT DESCRIPTION 4 PLLPRESCALE 0 0 = MCLK input not divided (default) 1= Divide MCLK by 2 before input to PLL R36 PLL N value 3:0 PLLN 1000 Integer (N) part of PLL input/output frequency ratio. Use values greater than 5 and less than 13. R37 PLL K value 1 5:0 PLLK [23:18] 0Ch R38 PLL K Value 2 8:0 PLLK [17:9] 093h R39 PLL K Value 3 8:0 PLLK [8:0] 0E9h Fractional (K) part of PLL1 input/output frequency ratio (treat as one 24-digit binary number). Table 47 PLL Frequency Ratio Control The PLL performs best when f2 is around 90MHz. Its stability peaks at N=8. Some example settings are shown in Table 48. MCLK (MHz) (F1) DESIRED OUTPUT (MHz) F2 (MHz) PRESCALE DIVIDE POSTSCALE DIVIDE R N (Hex) K (Hex) 12 11.2896 90.3168 1 2 7.5264 7 86C226 12 12.288 98.304 1 2 8.192 8 3126E8 13 11.2896 90.3168 1 2 6.947446 6 F28BD4 13 12.288 98.304 1 2 7.561846 7 8FD525 14.4 11.2896 90.3168 1 2 6.272 6 45A1CA 14.4 12.288 98.304 1 2 6.826667 6 D3A06E 19.2 11.2896 90.3168 2 2 9.408 9 6872AF 19.2 12.288 98.304 2 2 10.24 A 3D70A3 19.68 11.2896 90.3168 2 2 9.178537 9 2DB492 19.68 12.288 98.304 2 2 9.990243 9 FD809F 19.8 11.2896 90.3168 2 2 9.122909 9 1F76F7 19.8 12.288 98.304 2 2 9.929697 9 EE009E 24 11.2896 90.3168 2 2 7.5264 7 86C226 24 12.288 98.304 2 2 8.192 8 3126E8 26 11.2896 90.3168 2 2 6.947446 6 F28BD4 26 12.288 98.304 2 2 7.561846 7 8FD525 27 11.2896 90.3168 2 2 6.690133 6 BOAC93 27 12.288 98.304 2 2 7.281778 7 482296 Table 48 PLL Frequency Examples |
|
링크 URL |
| ALLDATASHEET 가 귀하에 도움이 되셨나요? [ DONATE ] |
Alldatasheet는? | 광고문의 | 운영자에게 연락하기 | 개인정보취급방침 | 링크 투 데이터시트 | 링크교환 | 제조사별 검색 All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |