- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄1931 > KSZ8864RMNI (Micrel Inc)IC ETHERNET SWITCH 4PORT 64QFN PDF資料下載
參數(shù)資料
| 型號： | KSZ8864RMNI |
| 廠商： | Micrel Inc |
| 文件頁數(shù)： | 54/111頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC ETHERNET SWITCH 4PORT 64QFN |
| 特色產(chǎn)品： | KSZ8864RMN Ethernet Switches |
| 標(biāo)準(zhǔn)包裝： | 348 |
| 系列： | * |
| 其它名稱： | 576-3995 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁當(dāng)前第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁
1997 Microchip Technology Inc.
DS30444E - page 47
PIC16C9XX
7.2
Using Timer0 with an External Clock
When an external clock input is used for Timer0, it must
meet certain requirements. The requirements ensure
the external clock can be synchronized with the internal
phase clock (TOSC). Also, there is a delay in the actual
incrementing of Timer0 after synchronization.
7.2.1
EXTERNAL CLOCK SYNCHRONIZATION
When no prescaler is used, the external clock input is
the same as the prescaler output. The synchronization
of T0CKI with the internal phase clocks is accom-
plished by sampling the prescaler output on the Q2 and
Q4 cycles of the internal phase clocks (Figure 7-5).
Therefore, it is necessary for T0CKI to be high for at
least 2Tosc (and a small RC delay of 20 ns) and low for
at least 2Tosc (and a small RC delay of 20 ns). Refer to
the electrical specication of the desired device.
When a prescaler is used, the external clock input is
divided by the asynchronous ripple-counter type pres-
caler so that the prescaler output is symmetrical. For
the external clock to meet the sampling requirement,
the ripple-counter must be taken into account. There-
fore, it is necessary for T0CKI to have a period of at
least 4Tosc (and a small RC delay of 40 ns) divided by
the prescaler value. The only requirement on T0CKI
high and low time is that they do not violate the mini-
mum pulse width requirement of 10 ns. Refer to param-
eters 40, 41 and 42 in the electrical specication of the
desired device.
7.2.2
TMR0 INCREMENT DELAY
Since the prescaler output is synchronized with the
internal clocks, there is a small delay from the time the
external clock edge occurs to the time the Timer0 mod-
ule is actually incremented. Figure 7-5 shows the delay
from the external clock edge to the timer incrementing.
FIGURE 7-5:
TIMER0 TIMING WITH EXTERNAL CLOCK
Q1
Q2 Q3 Q4
Q1 Q2 Q3 Q4
External Clock Input or
Prescaler output (2)
External Clock/Prescaler
Output after sampling
Increment Timer0 (Q4)
Timer0
T0
T0 + 1
T0 + 2
Small pulse
misses sampling
Note 1: Delay from clock input change to Timer0 increment is 3Tosc to 7Tosc. (Duration of Q = Tosc).
Therefore, the error in measuring the interval between two edges on Timer0 input =
±4Tosc max.
2: External clock if no prescaler selected, Prescaler output otherwise.
3: The arrows indicate the points in time where sampling occurs.
(3)
(1)
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| KSZ8873FLLI | IC ETHERNET SWITCH 3PORT 64LQFP |
| KSZ8873MLLJ | IC ETHERNET SWITCH 3PORT 64LQFP |
| KSZ8873MMLI | IC ETHERNET SWITCH 3PORT 64LQFP |
| KSZ8893FQL | IC SWITCH FAST ETH 3PORT 128PQFP |
| KSZ8895MQI | IC ETHERNET SWITCH 5PORT 128PQFP |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| KSZ8864RMNU | 功能描述:以太網(wǎng) IC 4-Port 10/100BT Switch with MII/RMII (Automotive) RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray |
| KSZ8864RMNU TR | 制造商:Micrel Inc 功能描述:IC ETHERNET SWITCH 4PORT 64MLF |
| KSZ8873FLL | 功能描述:以太網(wǎng) IC 3-Port Fast Ethernet Switch with 2x FX Ports - Lead free RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray |
| KSZ8873FLL-EVAL | 功能描述:以太網(wǎng)開發(fā)工具 3-Port Fast Ethernet Switch with 2x FX Ports - Evaluation Board RoHS:否 制造商:Micrel 產(chǎn)品:Evaluation Boards 類型:Ethernet Transceivers 工具用于評估:KSZ8873RLL 接口類型:RMII 工作電源電壓: |
| KSZ8873FLLI | 功能描述:以太網(wǎng) IC 3-Port Fast Ethernet Switch with 2x FX Ports (Industrial Grade) RoHS:否 制造商:Micrel 產(chǎn)品:Ethernet Switches 收發(fā)器數(shù)量:2 數(shù)據(jù)速率:10 Mb/s, 100 Mb/s 電源電壓-最大:1.25 V, 3.45 V 電源電壓-最小:1.15 V, 3.15 V 最大工作溫度:+ 85 C 封裝 / 箱體:QFN-64 封裝:Tray |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。