SC1100 datasheet(63/348 Pages) NSC

63 / 348 page

Revision 1.1

www.national.com

General Configuration Block (Continued)

3.5.6

Clock Registers

Table 3-8. Clock Generator Configuration

Bit

Description

Offset: 10h

Maximum Core Clock Multiplier Register - MCCM (RO)

Reset Value: Strapped Value

Width: Byte

This register holds the maximum core clock multiplier value. The maximum clock frequency allowed by the core, is the Fast-PCI clock

multiplied by this value.

7:4

Reserved.

3:0

MCM (Maximum Clock Multiplier). This 4-bit value is the maximum multiplier value allowed for the core clock generator. It

is derived from strap options CLKSEL[3:0] (balls AE22, AD22, AD25, D23).

Offset: 12h

PLL Power Control Register - PPCR (R/W)

Reset Value: 2Fh

Width: Byte

This register controls operation of the PLLs.

Reserved. Write as read.

EXPCID (Disable External PCI Clock).

0: External PCI clock is enabled.

1: External PCI clock is disabled.

Reserved. Must be written as 1.

Reserved. Write as read.

PLL3SD (Shut Down PLL3). AC97 codec clock.

0: PLL3 is enabled.

1: PLL3 is shutdown.

FM1SD (Shut Down PLL4).

0: PLL4 is enabled.

1: PLL4 is shutdown.

C48MD (Disable SuperI/O and USB Clock).

0: USB and SuperI/O clock is enabled.

1: USB and SuperI/O clock is disabled.

Reserved. Write as read.

Offset: 18h

PLL3 Configuration Register - PLL3C (R/W)

Reset Value: E1040005h

Width: DWORD

31:24

MFFC (MFF Counter Value).

FVCO

= OSCCLK * MFBC / (MFFC * MOC)

OSCCLK = 27 MHz

23:19

Reserved. Write as read.

18:8

MFBC (MFB Counter Value).

FVCO

= OSCCLK * MFBC / (MFFC * MOC)

OSCCLK = 27 MHz

Reserved. Write as read.

Reserved. Must be set to 0.

5:0

MOC (MO Counter Value).

FVCO

= OSCCLK * MFBC / (MFFC * MOC)

OSCCLK = 27 MHz

SC1100 Datasheet(PDF) 63 Page - National Semiconductor (TI)

SC1100 Datasheet(HTML) 63 Page - National Semiconductor (TI)

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL