參數(shù)資料
型號(hào): CYW311OXCT
廠商: SILICON LABORATORIES
元件分類: 時(shí)鐘產(chǎn)生/分配
英文描述: 200 MHz, PROC SPECIFIC CLOCK GENERATOR, PDSO48
封裝: LEAD FREE, SSOP-48
文件頁數(shù): 5/18頁
文件大?。?/td> 287K
代理商: CYW311OXCT
W311
....................... Document #: 38-07703 Rev. ** Page 13 of 18
How to Program CPU Output Frequency
When the programmable output frequency feature is enabled
(Pro_Freq_EN bit is set), the CPU output frequency is deter-
mined by the following equation:
Fcpu = G * (N+3)/(M+3)
“N” and “M” are the values programmed in Programmable
Frequency Select N-Value Register and M-Value Register,
respectively.
“G” stands for the PLL Gear Constant, which is determined by
the programmed value of FS[4:0] or SEL[4:0]. The value is
listed in Table 5. The ratio of (N+3) and (M+3) need to be
greater than “1” [(N+3)/(M+3) > 1].
Table 7 lists set of N and M values for different frequency
output ranges.This example use a fixed value for the M-Value
Register and select the CPU output frequency by changing the
value of the N-Value Register.
FS_Override
When Pro_Freq_EN is cleared or disabled,
0 = Select operating frequency by FS input pins (default)
1 = Select operating frequency by SEL bits in SMBus control bytes
When Pro_Freq_EN is set or enabled,
0 = Frequency output ratio between CPU and other frequency groups and the PLL Gear Constant are
based on the latched value of FS input pins (default)
1 = Frequency output ratio between CPU and other frequency groups and the PLL Gear Constant are
based on the programmed value of SEL bits in SMBus control bytes
CPU_FSEL_N,
CPU_FSEL_M
ROCV_FREQ_SEL
When Prog_Freq_EN is set or enabled, the values programmed in CPU_FSEL_N[7:0] and
CPU_FSEL_M[6:0] determines the CPU output frequency. The new frequency will start to load
whenever there is an update to either CPU_FSEL_N[7:0] or CPU_FSEL_M[6:0]. Therefore, it is recom-
mended to use Word or Block write to update both registers within the same SMBus bus operation.
The setting of FS_Override bit determines the frequency ratio for CPU, AGP and PCI. When
FS_Override is cleared or disabled, the frequency ratio follows the latched value of the FS input pins.
When FS_Override is set or enabled, the frequency ratio follows the programmed value of SEL bits in
SMBus control bytes.
ROCV_FREQ_SEL determines the source of the recover frequency when a Watchdog Timer timeout
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]
WD_PRE_SCALER
0 = 150 ms
1 = 2.5 sec
RST_EN_WD
This bit will enable the generation of a Reset pulse when a Watchdog timer time-out occurs.
0 = Disabled
1 = Enabled
RST_EN_FC
This bit will enable the generation of a Reset pulse after a frequency change occurs.
0 = Disabled
1 = Enabled
Table 6. Register Summary (continued)
Name
Description
Table 7. Examples of N and M Value for Different CPU Frequency Range
Frequency Ranges
Gear Constants
Fixed Value for
M-Value Register
Range of N-Value Register
for Different CPU Frequency
50 MHz–129 MHz
48.00741
93
97–255
130 MHz–248 MHz
48.00741
45
127–245
相關(guān)PDF資料
PDF描述
CZ23EH-FREQ-OUT23 VCXO, CLOCK, 1.25 MHz - 65 MHz, CMOS/TTL OUTPUT
CZM4-2000 VCO, 1950 MHz - 2800 MHz
CZSH5-40C 2.5 A, 40 V, SILICON, RECTIFIER DIODE
D-20C 8 FUNCTIONS, 50 V, 0.5 A, DATA LINE FILTER
D00EEB-0001 5 CONTACT(S), FEMALE, CIRCULAR CONNECTOR, CRIMP/SOLDER, RECEPTACLE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
CYW312OXC 制造商:SPECTRALINEAR 制造商全稱:SPECTRALINEAR 功能描述:FTG for VIA⑩ K7 Series Chipset with Programmable Output Frequency
CYW312OXCT 制造商:CYPRESS 制造商全稱:Cypress Semiconductor 功能描述:FTG for VIA⑩ K7 Series Chipset with Programmable Output Frequency
CYW320OXC-3 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 Legacy, W320-03 datasheet RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel
CYW320OXC-3T 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 Legacy, W320-03 datasheet RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel
CYW320OXC-4 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 Legacy, W320-04 datasheet RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel