W312-02 Datasheet, PDF (11/21 Pages) Cypress Semiconductor – FTG for VIA K7 Series Chipset with Programmable Output Frequency

W312-02
Byte 12: Recovery Frequency M- Value Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Name
ROCV_FREQ_SEL
ROCV_FREQ_M6
ROCV_FREQ_M5
ROCV_FREQ_M4
ROCV_FREQ_M3
ROCV_FREQ_M2
ROCV_FREQ_M1
ROCV_FREQ_M0
Default
0
0
0
0
0
0
0
0
Pin Description
ROCV_FREQ_SEL determines the source of the recover frequency when a
Watchdog timer time-out occurs. The clock generator will automatically switch
to the recovery CPU frequency based on the selection on ROCV_FREQ_SEL.
0 = From latched FS[4:0]
1 = From the settings of ROCV_FREQ_N[7:0] & ROCV_FREQ_M[6:0]
If ROCV_FREQ_SEL is set, W312-02 will use the values programmed in
ROCV_FREQ_N[7:0] and ROCV_FREQ_M[6:0] to determine the recovery
CPU output frequency.when a Watchdog timer time-out occurs
The setting of FS_Override bit determines the frequency ratio for CPU,
SDRAM, AGP and SDRAM. When it is cleared, W312-02 will use the same
frequency ratio stated in the Latched FS[4:0] register. When it is set, W312-
02 will use the frequency ratio stated in the SEL[4:0] register.
W312-02 supports programmable CPU frequency ranging from 50 MHz to
248 MHz.
W312-02 will change the output frequency whenever there is an update to
either ROCV_FREQ_N[7:0] and ROCV_FREQ_M[6:0]. Therefore, it is rec-
ommended to use Word or Block write to update both registers within the
same SMBus bus operation.
Byte 13: Programmable Frequency Select N-Value Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Name
CPU_FSEL_N7
CPU_FSEL_N6
CPU_FSEL_N5
CPU_FSEL_N4
CPU_FSEL_N3
CPU_FSEL_N2
CPU_FSEL_N1
CPU_FSEL_N0
Default
Pin Description
0
If Prog_Freq_EN is set, W300 will use the values programmed in
CPU_FSEL_N[7:0] and CPU_FSEL_M[6:0] to determine the CPU output fre-
0
quency. The new frequency will start to load whenever CPU_FSELM[6:0] is
0
updated.
The setting of FS_Override bit determines the frequency ratio for CPU,
0
SDRAM, AGP and SDRAM. When it is cleared, W312 will use the same
frequency ratio stated in the Latched FS[4:0] register. When it is set, W312-
0
02 will use the frequency ratio stated in the SEL[4:0] register.
0
W312-02 supports programmable CPU frequency ranging from 50 MHz to
248 MHz.
0
0
Byte 14: Programmable Frequency Select N-Value Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Name
Pro_Freq_EN
CPU_FSEL_M6
CPU_FSEL_M5
CPU_FSEL_M4
CPU_FSEL_M3
CPU_FSEL_M2
CPU_FSEL_M1
CPU_FSEL_M0
Default
Description
0
Programmable output frequencies enabled
0 = disabled
1 = enabled
0
If Prog_Freq_EN is set, W300 will use the values programmed in
CPU_FSEL_N[7:0] and CPU_FSEL_M[6:0] to determine the CPU output fre-
0
quency. The new frequency will start to load whenever CPU_FSELM[6:0] is
0
updated.
The setting of FS_Override bit determines the frequency ratio for CPU,
0
SDRAM, AGP and SDRAM. When it is cleared, W312-02 will use the same
frequency ratio stated in the Latched FS[4:0] register. When it is set, W312-
0
02 will use the frequency ratio stated in the SEL[4:0] register.
0
W312-02 supports programmable CPU frequency ranging from 50 MHz to
248 MHz.
0
Document #: 38-07259 Rev. *B
Page 11 of 21