The KSZMNX offers the industry-standard GMII/MII Media Independent Interface (GMII) is compliant to the IEEE Specification. Dave Fifield [email protected] GMII Electrical Specification IEEE Interim Meeting, San Diego, January N. Interface) for connection to GMII/MII MACs in Gigabit . Clarified power cycling specification to have all supply voltages to the KSZMNX.
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Input high threshold is 2. Transmit and receive path each use one differential pair for data and another differential pair for clock.
The media-independent interface MII was originally defined as a standard interface to connect a Fast Ethernet i.
It is not to be confused with RM2. Carrier sense is high when transmitting, receiving, or the medium is otherwise sensed as being in use. Source-synchronous clocking is spedification If a collision is detected, COL also goes high while the collision persists. Typically used for on-chip connections; in chip-to-chip usage mostly replaced by XAUI.
Retrieved from ” https: There are 32 addresses, each containing 16 bits.
This requires the PCB to be designed to add a specificaation. Given trends in the semiconductor industry and the fact that both ICs are usually on the same board, lack of 5 V tolerance is probably very common, and chips that actually drive 5 V are probably even rarer.
Four things were changed compared to the MII standard to achieve this:. It contains a bitmask with the following meaning: For this reason, the reduced media independent interface was developed. Received clock signal recovered from incoming received data.
This may be used to abort a frame when some problem is detected after transmission has already started. This interface requires 9 signals, versus MII’s For receive, two data values are defined: Views Read Edit View history.
This arrangement allows the MAC specidication operate without having to be aware of the link speed.
TTL signal levels are used for 5 V or 3. This means a slight modification of the definition of CRS: Ethernet Computer buses Serial buses. The RMII signals are treated as lumped signals rather than transmission lines; no termination or controlled impedance is necessary; output drive and thus slew rates need to be as slow as possible rise times from 1—5 ns to permit this.
The first 16 addresses have a defined usage,  while the others are device specific. These registers can be used to configure the device say “only gigabit, full duplex”, or “only full duplex” or can be used to determine the current operating mode. Being media independent means that different types of PHY devices for connecting to different media i.
Archived from the original on The specification states that inputs should be 5 V tolerant, however, some popular chips with RMII interfaces are not 5 V tolerant.
Media-independent interface – Wikipedia
At least the standard says the signals need not be treated as transmission lines. The receive clock is recovered from the incoming signal during frame reception.
Ethernet family of local area network technologies. However, at 1 ns edge rates a trace longer than about 2. At power up, using autonegotiationthe PHY usually adapts to whatever it is connected to unless settings are altered via the MDIO interface. The management interface controls the behavior of the PHY. Reference clock may be an input on both devices from an external clock source, or may be driven from the MAC to the PHY. The original MII transfers specifidation data ggmii 4-bit nibbles in each direction 4 transmit data bits, 4 receive data bits.
Transmit error may be raised for one or more clock periods during frame transmission to request the PHY to deliberately corrupt the frame in some visible way that precludes it from being received as valid. The original MII design has been extended to support reduced signals and increased speeds. There is no signal which defines whether the interface is in full or half duplex mode, but both the MAC and the PHY need to agree. When no clock can be recovered i.
More recently, raising transmit error outside frame transmission is used to indicate the transmit data lines are being used for special-purpose signalling. As such it consists of a preamble, start frame delimiter, Ethernet headers, protocol specific data and a cyclic redundancy check CRC. Current revisions of IEEE