Operating at 2. San Jose, CA ? Tel 1 ? RXD [ Digital IO 2. Gnd Ground Pwr Digital core 2.
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Operating at 2. San Jose, CA ? Tel 1 ? RXD [ Digital IO 2. Gnd Ground Pwr Digital core 2. The 4,3 default PHY address is If Duplex is pulled up during reset, this pin also latched as the Duplex support in register 4h. Mode RO Default 0 1f.
An isolation transformer with integrated common-mode choke is recommended for exceeding FCC requirements. The following table gives recommended transformer characteristics. Leakage Inductance max. Inter-Winding Capacitance max. Resistance max. Insertion Loss max.
HIPOT min. For the transmit line transformer, insertion loss of up to 1. Characteristics Name Frequency Frequency Tolerance max. Load Capacitance max. Series Resistance max. Value The circuitry starts with a parallel to serial conversion, which converts the 25 MHz, 4-bit nibbles into a MHz serial bit stream.
The incoming data is clocked in at the positive edge of the TXC signal. The receiving side starts with the equalization filter to compensate intersymbol interference ISI over the twisted pair cable.
Since the amplitude loss and phase distortion are a function of the length of the cable, the equalizer has to adjust its characteristic to optimize the performance. In this design, the variable equalizer will make an initial estimation based on comparisons of incoming signal strength against some known cable characteristics, then tunes itself for optimization. This is an ongoing process and can self adjust against the environmental changes such as temperature variations.
The equalized signal then goes through a DC restoration and data conversion block. The DC restoration circuit is used to compensate effect of base line wander and improve the dynamic range.
The slicing threshold is also adaptive. Finally, the NRZ serial data is converted to 4-bit parallel 4B nibbles.
An internal crystal oscillator circuit provides the reference clock for the synthesizer. The data transmission will end when TXEN goes low. The last transition occurs at the boundary of the bit cell if the last bit is zero, or at the center of the bit cell if the last bit is one.
The output driver is incorporated into the Base driver to allow transmission with the same magnetics. They are internally wave-shaped and preemphasized into outputs with a typical 2. The harmonic contents are at least 27 dB below the fundamental when driven by an all-ones Manchester-encoded signal.
A differential input receiver circuit and a PLL performs the decoding function. The Manchester-encoded data stream is separated into clock signal and NRZ data. The receive clock is maintained active during idle periods in between data reception.
It will automatically choose its mode of operation by advertising its abilities and comparing them with those received from its link partner whenever auto-negotiation is enabled.
It can also be configured to advertise BaseTX or 10BaseT in either full- or half-duplex mode please refer to page 11 and 12 for setting. The auto-negotiation is disabled in the FX mode. During auto-negotiation, the contents of Register 4, coded in Fast Link Pulse FLP , will be sent to its link partner under the conditions of power-on, link-loss or re-start.
The MDIO interface consists of the following:? An internal addressable set of fourteen bit MDIO registers. Register  are required and their functions are specified by the IEEE Additional registers are provided for expanded functionality.
Register bits at 1bh are the interrupt enable bits. Register bits at 1bh are the interrupt condition bits.
This interrupt is cleared by reading Register 1bh. Normal data transmission is implemented in 4B Nibble Mode 4-bit wide nibbles. If the link goes down, and auto-negotiation is disabled, the receive clock operates off the master input clock X1 or TXC. For 10BaseT links, the receive clock is recovered from the line while carrier is active, and operates from the master input clock when the line is idle. For 10BaseT links, the entire preamble is truncated.
It is fully compliant with IEEE This interface has the following characteristics: 1. It provides independent 2 bit wide di-bit transmit and receive data paths 4. In some cases e. During the IPG time following the successful transmission of a frame, the COL signal is asserted by some transceivers as a self-test. This feature can eliminate the confusion in real applications so both straight cable and crossover cable can be used.
Power Down Mode: This mode can be achieved by writing to Register 0. Power Saving Mode: writing to register 1fh. Power Saving mode will be in his most effective state when Auto-Negotiation Mode is enable.
Under this mode, the auto-negotiation and auto-MDIX features are disabled. The internal threshold of FXSD is around? A resistive voltage divider is recommended to adjust the SD voltage range.
The purpose of FEF is to notify the sender of a faulty link. One part is operating at TX mode and the other in FX mode. Both parts can share a common 50MHz oscillator. Under this operation, auto-Negotiation on the TX side will prohibit 10baseT link up. TXD2, active High, can disable transmitter and set it at tri-state. RXD2 serves as energy detection can indicate if there is line signal detected. Operation of the device at these or any other conditions above those specified in the operating sections of this specification is not implied.
Maximum conditions for extended periods may affect reliability. Unused inputs must always be tied to an appropriate logic voltage level Ground or Vdd. COM The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that a are intended for surgical implant into the body or b support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user.
KS8721BL PDF Datasheet浏览和下载
Dikora Power consumption should be as low as possible. I downloaded the datasheet. Ethernet PHY requirements revised e. Enhanced link detection requires proper PHY address configuration. Yes, I saw nothing as well on my board until I decided to remove the part. Slave Controller — Application Note 1. All rights reserved in the event of the grant of a patent, utility model or design.
Mikak The SAM7X has to be carefully controlled during chip startup since its internal pullups cause a bit of a difficulty when the PHY configures itself over the hardware settings read at reset. Devices with one or more EBUS ports which do not support port-wise configuration can not be configured to use Enhanced link detection. The signal polarity is active low or configurable for some ESCs. Only for single port devices, because only one PHY address can be used. Please send an email to an address at the bottom of the home page with your preferred user name and email address if you would like an account. Ah ah, it is interesting!