- 您现在的位置：买卖IC网 > PDF目录16826 > KSZ8864RMN-EVAL (Micrel Inc)BOARD EVALUATION FOR KSZ8864RMN PDF资料下载
参数资料
| 型号： | KSZ8864RMN-EVAL |
| 厂商： | Micrel Inc |
| 文件页数： | 61/111页 |
| 文件大小： | 0K |
| 描述： | BOARD EVALUATION FOR KSZ8864RMN |
| 标准包装： | 1 |
| 主要目的： | 接口，以太网控制器（PHY 和 MAC） |
| 嵌入式： | 否 |
| 已用 IC / 零件： | KSZ8864RMN |
| 已供物品： | 板 |
| 相关产品： | 576-3787-ND - IC ETHERNET SW 4PORT 64QFN |
| 其它名称： | 576-3869 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页当前第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页
1997 Microchip Technology Inc.
DS30444E - page 53
PIC16C9XX
8.3
Timer1 Operation in Asynchronous
Counter Mode
If control bit T1SYNC (T1CON<2>) is set, the external
clock input is not synchronized. The timer continues to
increment asynchronous to the internal phase clocks.
The timer will continue to run during SLEEP and can
generate an interrupt on overow which will wake-up
the processor. However, special precautions in soft-
ware are needed to read-from or write-to the Timer1
register pair (TMR1H:TMR1L) (Section 8.3.2).
In asynchronous counter mode, Timer1 cannot be used
as a time-base for capture or compare operations.
8.3.1
EXTERNAL CLOCK INPUT TIMING WITH
UNSYNCHRONIZED CLOCK
If control bit T1SYNC is set, the timer will increment
completely asynchronously. The input clock must meet
certain minimum high time and low time requirements,
as specied in timing parameters 45, 46, and 47.
8.3.2
READING AND WRITING TMR1 IN
ASYNCHRONOUS COUNTER MODE
Reading TMR1H or TMR1L while the timer is running,
from an external asynchronous clock, will ensure a
valid read (taken care of in hardware). However, the
user should keep in mind that reading the 16-bit timer
in two 8-bit values itself poses certain problems since
the timer may overow between the reads.
For writes, it is recommended that the user simply stop
the timer and write the desired values. A write conten-
tion may occur by writing to the timer registers while the
register is incrementing. This may produce an unpre-
dictable value in the timer register.
Reading
the
16-bit
value
requires
some
care.
Example 8-1 is an example routine to read the 16-bit
timer value. This is useful if the timer cannot be
stopped.
EXAMPLE 8-1:
READING A 16-BIT
FREE-RUNNING TIMER
; All interrupts are disabled
MOVF
TMR1H, W
;Read high byte
MOVWF
TMPH
;
MOVF
TMR1L, W
;Read low byte
MOVWF
TMPL
;
MOVF
TMR1H, W
;Read high byte
SUBWF
TMPH,
W
;Sub 1st read
; with 2nd read
BTFSC
STATUS,Z
;Is result = 0
GOTO
CONTINUE
;Good 16-bit read
;
; TMR1L may have rolled over between the read
; of the high and low bytes. Reading the high
; and low bytes now will read a good value.
;
MOVF
TMR1H, W
;Read high byte
MOVWF
TMPH
;
MOVF
TMR1L, W
;Read low byte
MOVWF
TMPL
;
; Re-enable the Interrupt (if required)
CONTINUE
;Continue with your code
8.4
Timer1 Oscillator
A crystal oscillator circuit is built in between pins T1OSI
(input) and T1OSO (amplier output). It is enabled by
setting control bit T1OSCEN (T1CON<3>). The oscilla-
tor is a low power oscillator rated up to 200 kHz. It will
continue to run during SLEEP. It is primarily intended
for a 32 kHz crystal. Table 8-1 shows the capacitor
selection for the Timer1 oscillator.
The Timer1 oscillator is identical to the LP oscillator.
The user must provide a software time delay to ensure
proper oscillator start-up.
TABLE 8-1: CAPACITOR SELECTION FOR
THE TIMER1 OSCILLATOR
Osc Type
Freq
C1
C2
LP
32 kHz
33 pF
100 kHz
15 pF
200 kHz
15 pF
These values are for design guidance only.
Crystals Tested:
32.768 kHz
Epson C-001R32.768K-A
± 20 PPM
100 kHz
Epson C-2 100.00 KC-P
± 20 PPM
200 kHz
STD XTL 200.000 kHz
± 20 PPM
Note 1: Higher capacitance increases the stability
of oscillator but also increases the start-up
time.
2: Since each resonator/crystal has its own
characteristics, the user should consult the
resonator/crystal manufacturer for appropri-
ate values of external components.
相关PDF资料 |
PDF描述 |
|---|---|
| 362A024-3/42-0 | BOOT MOLDED |
| 0210391088 | CABLE JUMPER 1MM .203M 37POS |
| 570-002-744-200 | ASSEMBLY RECEPT 2 POS WATERPROOF |
| 202D285-4/42-0 | BOOT MOLDED |
| 0210391087 | CABLE JUMPER 1MM .178M 37POS |
相关代理商/技术参数 |
参数描述 |
|---|---|
| KSZ8864RMNI | 功能描述:以太网 IC 4-Port 10/100 Ethernet Switch w/ 2x PHYs and 2x MAC Interface - Industrial Temp RoHS:否 制造商:Micrel 产品:Ethernet Switches 收发器数量:2 数据速率:10 Mb/s, 100 Mb/s 电源电压-最大:1.25 V, 3.45 V 电源电压-最小:1.15 V, 3.15 V 最大工作温度:+ 85 C 封装 / 箱体:QFN-64 封装:Tray |
| KSZ8864RMNU | 功能描述:以太网 IC 4-Port 10/100BT Switch with MII/RMII (Automotive) RoHS:否 制造商:Micrel 产品:Ethernet Switches 收发器数量:2 数据速率:10 Mb/s, 100 Mb/s 电源电压-最大:1.25 V, 3.45 V 电源电压-最小:1.15 V, 3.15 V 最大工作温度:+ 85 C 封装 / 箱体:QFN-64 封装:Tray |
| KSZ8864RMNU TR | 制造商:Micrel Inc 功能描述:IC ETHERNET SWITCH 4PORT 64MLF |
| KSZ8873FLL | 功能描述:以太网 IC 3-Port Fast Ethernet Switch with 2x FX Ports - Lead free RoHS:否 制造商:Micrel 产品:Ethernet Switches 收发器数量:2 数据速率:10 Mb/s, 100 Mb/s 电源电压-最大:1.25 V, 3.45 V 电源电压-最小:1.15 V, 3.15 V 最大工作温度:+ 85 C 封装 / 箱体:QFN-64 封装:Tray |
| KSZ8873FLL-EVAL | 功能描述:以太网开发工具 3-Port Fast Ethernet Switch with 2x FX Ports - Evaluation Board RoHS:否 制造商:Micrel 产品:Evaluation Boards 类型:Ethernet Transceivers 工具用于评估:KSZ8873RLL 接口类型:RMII 工作电源电压: |
发布紧急采购，3分钟左右您将得到回复。