SMBus provides a clock synchronization mechanism, similar to I
參數(shù)資料
型號: DTMFDECODER-RD
廠商: Silicon Laboratories Inc
文件頁數(shù): 18/178頁
文件大?。?/td> 0K
描述: KIT REF DESIGN DTMF DECODER
應(yīng)用說明: DTMF Decoder Ref Design AppNote
標準包裝: 1
主要目的: 電信,DTMF 解碼器
嵌入式:
已用 IC / 零件: C8051F300
主要屬性: 8kHz 采樣速率模數(shù)轉(zhuǎn)換器
次要屬性: 16 個 Goertzel 濾波器
已供物品: 板,軟件
產(chǎn)品目錄頁面: 627 (CN2011-ZH PDF)
相關(guān)產(chǎn)品: 336-1535-5-ND - IC 8051 MCU 8K FLASH 14-SOIC
C8051F300-GMR-ND - IC 8051 MCU 8K FLASH 11QFN
336-1245-ND - IC 8051 MCU 8K FLASH 11QFN
其它名稱: 336-1283
C8051F300/1/2/3/4/5
114
Rev. 2.9
13.3.2. Clock Low Extension
SMBus provides a clock synchronization mechanism, similar to I2C, which allows devices with different
speed capabilities to coexist on the bus. A clock-low extension is used during a transfer in order to allow
slower slave devices to communicate with faster masters. The slave may temporarily hold the SCL line
LOW to extend the clock low period, effectively decreasing the serial clock frequency.
13.3.3. SCL Low Timeout
If the SCL line is held low by a slave device on the bus, no further communication is possible. Furthermore,
the master cannot force the SCL line high to correct the error condition. To solve this problem, the SMBus
protocol specifies that devices participating in a transfer must detect any clock cycle held low longer than
25 ms as a “timeout” condition. Devices that have detected the timeout condition must reset the communi-
cation no later than 10 ms after detecting the timeout condition.
When the SMBTOE bit in SMB0CF is set, Timer 2 is used to detect SCL low timeouts. Timer 2 is forced to
reload when SCL is high, and allowed to count when SCL is low. With Timer 2 enabled and configured to
overflow after 25 ms (and SMBTOE set), the Timer 2 interrupt service routine can be used to reset (disable
and reenable) the SMBus in the event of an SCL low timeout. Timer 2 configuration details can be found in
13.3.4. SCL High (SMBus Free) Timeout
The SMBus specification stipulates that if the SCL and SDA lines remain high for more that 50 s, the bus
is designated as free. When the SMBFTE bit in SMB0CF is set, the bus will be considered free if SCL and
SDA remain high for more than 10 SMBus clock source periods. If the SMBus is waiting to generate a
Master START, the START will be generated following this timeout. Note that a clock source is required for
free timeout detection, even in a slave-only implementation.
相關(guān)PDF資料
PDF描述
UPZ2E121MND9 CAP ALUM 120UF 250V 20% RADIAL
A3KKB-1036M IDC CABLE - APK10B/AE10M/APK10B
UVR2G101MRD6 CAP ALUM 100UF 400V 20% RADIAL
LLS2A102MELZ CAP ALUM 1000UF 100V 20% SNAP
SI5310-EVB BOARD EVALUATION FOR SI5310
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DTMG5812L WAF 制造商:ON Semiconductor 功能描述:
DTMG5852L WAF 制造商:ON Semiconductor 功能描述:
DTMH04-2PA 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE DTM HI TEMP A KEY 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, A KEY, 2WAY, Series:DTMH, No. of Positions:2, Gender:Receptacle, No. of Rows:1 , RoHS Compliant: Yes
DTMH04-2PB 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE DTM HI TEMP B KEY 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, B KEY, 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, B KEY, 2WAY; Series:DTMH; Gender:Receptacle; No. of Contacts:2; No. of Rows:1; Contact Gender:Pin; Connector Mounting:Cable; Connector Shell Size:-; Contact Termination:Crimp; Contact Material:Copper; Contact;RoHS Compliant: Yes
DTMH04-2PC 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE DTM HI TEMP C KEY 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, C KEY, 2WAY 制造商:TE Connectivity / Deutsch 功能描述:RECEPTACLE, DTM HI TEMP, C KEY, 2WAY; Series:DTMH; Gender:Receptacle; No. of Contacts:2; No. of Rows:1; Contact Gender:Pin; Connector Mounting:Cable; Connector Shell Size:-; Contact Termination:Crimp; Contact Material:Copper; Contact;RoHS Compliant: Yes