Motorola MSC8101 ADS User's Guide Page 55

  • Download
  • Add to my manuals
  • Print
  • Page
    / 346
  • Table of contents
  • BOOKMARKS
  • Rated. / 5. Based on customer reviews
Page view 54
Reset Configuration and Boot Basics
Reset Configuration and Boot 2-3
multiplication factor is determined by the values of the SPLL pre-division factor and the
SPLL multiplication factor.
The SPLL provides the input clock to the frequency divider for the PowerPC 60x buses.
The bus multiplication factor is therefore determined by the combination of the SPLL
pre-division factor, the SPLL multiplication factor, and the bus post-division factor. The
bus clock is the input reference clock to the CPLL predivider.
The serial communications controller (SCC) clock post-division factor has a constant
value of four. The value of the baud-rate generator (BRG) clock post-division factor is set
using the System Clock Control Register (SCCR), as described in the clocks chapter of the
MSC8101 Reference Manual. The DLL performs clock skew elimination, as described in
detail in the clocks chapter of the MSC8101 Reference Manual. Figure 2-1 shows the
block diagram of the MSC8101 clocking structure.
Figure 2-1. MSC8101 Clocking Structure
The MSC8101 supports the following set of frequency ratios:
Ratios between the PowerPC system bus clock and the CPM clocklimited to
1:1.5, 1:2, 1:2.5.
Ratios between the PowerPC system bus clock and the SC140 core clocklimited
to 1:3, 1:4, 1:5, 1:6.
The phase lock between the PowerPC system bus clock and CLKIN is guaranteed for
ratio 1:1 only.
BCLK, BCLK_90
CPMCLK, CPMCLK_90
CLKIN
2xf
CPM
2xf
CPM
SCLK, SCLK_90
BRGCLK
CLKOUT
PDF: Pre-division factor
MF: Multiplication factor
DF: Post-division factor
PREDIV: Predivider
POSTDIV: Postdivider
DLL
Bus
POSTDIV
(DF)
SCC, BRG
POSTDIV
(DF) = 4
CPM
POSTDIV
(DF) = 2
CKO
POSTDIV
(DF)
SCC, BRG,
POSTDIV
(DF)
SPLL
(PDF)
SPLL
(MF)
Page view 54
1 2 ... 50 51 52 53 54 55 56 57 58 59 60 ... 345 346

Comments to this Manuals

No comments