W311 Datasheet, PDF (11/19 Pages) Silicon Laboratories – FTG for VIA™ Pro-266 DDR Chipset

W311
Byte 14: Programmable Frequency Select M-Value Register
Bit
Name
Default
Description
Bit 7
Pro_Freq_EN
0
Programmable output frequencies enabled
0 = disabled
1 = enabled
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CPU_FSEL_M6
CPU_FSEL_M5
CPU_FSEL_M4
CPU_FSEL_M3
CPU_FSEL_M2
CPU_FSEL_M1
CPU_FSEL_M0
0
If Prog_Freq_EN is set, W311 will use the values programmed in
0
CPU_FSEL_N[7:0] and CPU_FSEL_M[6:0] to determine the CPU output fre-
quency. The new frequency will start to load whenever CPU_FSELM[6:0] is
0
updated.
0
The setting of FS_Override bit determines the frequency ratio for CPU,
SDRAM, AGP and SDRAM. When it is cleared, W311 will use the same fre-
0
quency ratio stated in the Latched FS[4:0] register. When it is set, W311 will
0
use the frequency ratio stated in the SEL[4:0] register.
W311 supports programmable CPU frequency ranging from 50MHz to
0
248MHz.
Byte 15: Reserved Register
Bit
Pin#
Bit 7
47
Bit 6
6
Bit 5
7
Bit 4
21
Bit 3
22
Bit 2
-
Bit 1
-
Bit 0
-
Name
Latched FS4 input
Latched FS3 input
Latched FS2 input
Latched FS1 input
Latched FS0 input
Vendor test mode
Vendor test mode
Vendor test mode
Default
X
X
X
X
X
0
1
1
Description
Latched FS[4:0] inputs. These bits are read only.
Reserved. Write with ‘0’.
Reserved. Write with ‘1’
Reserved. Write with ‘1’
Byte 16: Reserved Register
Bit
Bit 7
Bit 6
Bit 5
Pin#
-
-
-
Bit 4
-
Bit 3
-
Bit 2
-
Bit 1
-
Bit 0
-
Name
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Default
0
0
0
0
0
0
0
0
Description
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Byte 17: Reserved Register
Bit
Bit 7
Bit 6
Pin#
-
-
Bit 5
-
Bit 4
-
Bit 3
-
Name
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Vendor test mode
Default
0
0
0
0
0
Description
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
Reserved. Write with ‘0’.
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