CY28372
Byte 12
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
@Pup
Name
Description
REF_2 Output Control (default: off)
0
0
0
0
0
0
REF_2
Reserved
Reserved
DARAG2
DARAG1
DARAG0
Reserved
Reserved
Dial-a-Ratio¥ AGP[0:1].
Programming these bits allow modifying the frequency ratio of the
AGP(1:0), PCI(5:0) and PCIF(0:1) clocks relative to the VCO. (the ratio
of AGP to PCI is retained at 2:1)
DARAG[2:0]
000
VC0/AGP Ratio
- (Frequency Selection Default)
001
010
6
8
011
100
101
110
9
10
12
12
12
111
Bit 1
0
0
Fixed_PCI_SEL
Fixed_3V66_SEL
PCI output frequency select mode
(valid only when Fixed_3V66_SEL = 1)
0 = Use Frequency Selection Table settings
1 = Use Fractional Aligner settings (default)
Bit 0
3V66 and PCI output frequency select mode
0 = Use Frequency Selection Table settings (default)
1 = Use Fractional Aligner settings
Byte 13
Bit
@Pup
Name
Description
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
Reserved
N6 (MSB)
N5
Reserved
Dial-a-Frequency® Control Register N. These bits are for programming
the PLL’s internal N register. This access allows the user to modify the
CPU frequency with great accuracy. All other synchronous clocks (clocks
that are generated from the same PLL, such as PCI, remain at their
existing ratios relative to the CPU clock. (should be written together with
Control Register R)
N4
N3
N2
N1
N0 (LSB)
Byte 14
Bit
@Pup
Name
Reserved
R5 (MSB)
R4
Pin Description
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
Reserved
Dial-a-Frequency Control Register R
These bits are for programming the PLL’s internal R register. This access
allowsthe usertomodifytheCPU frequencywithgreat accuracy. Allother
synchronous clocks (clocks that are generated from the same PLL, such
as PCI, remain at their existing ratios relative to the CPU clock.
(should be written together with Control Register N)
R3
R2
R1
R0 (LSB)
R & N Select
R and N register mux selection.
0 = R and N values come from the ROM.
1 = data is loaded from the DAF registers into R and N.
Rev 1.0,November 20, 2006
Page 8 of 17
SPECTRALINEAR [ SPECTRALINEAR INC ]
