DM8603EP DAVICOM [Davicom Semiconductor, Inc.], DM8603EP Datasheet - Page 72

• Manufacturer Part Number: DM8603EP
• Description: 10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
• Manufacturer: DAVICOM [Davicom Semiconductor, Inc.]

9.2.6
transmitted, the packet is dropped.
9.2.7
the receive side, The DM8603 will defer transmitting next normal frames, if it receives a pause frame from
link partner. On the transmit side, The DM8603 issues pause frame with maximum pause time when internal
resources such as received buffers, transmit queue and transmit descriptor ring are unavailable. Once
resources are available, The DM8603 sends out a pause frame with zero pause time allows traffic to resume
immediately.
9.2.8
flow control is required, the DM8603 sends jam pattern and results in a collision. The flow control ability can
be set in REG 08h/09h/0Ah.11h.[5].
9.2.9
partition mode when more than 64 consecutive collisions are occurred. In partition mode the port continuous
to transmit but it will not receive. The port returned to normal operation mode when a good packet is seen on
the wire. The detail description of partition mode represent following:
Preliminary datasheet
DM8603-12-DS-P01
November 8, 2010
Late Collision is a type of collision. If a collision error occurs after the first 512 bit times of data are
The DM8603 supports IEEE standard 802.3x flow control frames on both transmit and receive sides. On
The DM8603 supports half-duplex backpressure. The inducement is the same as full duplex mode. When
The DM8603 provides a partition mode for each port, see REG 08h/09h/0Ah.11h.[6]. The port enters
(1). Entering Partition State
(2). While in Partition State:
(3). Exiting from Partition State
Late Collision
Full Duplex Flow Control
Half Duplex Flow Control
Partition Mode
A port will enter the Partition State when either of the following conditions occurs:
The port will continue to transmit its pending packet, regardless of the collision detection, and will
not allow the usual Back-off Algorithm. Additional packets pending for transmission will be
transmitted, while ignoring the internal collision indication. This frees up the ports transmit buffers
which would otherwise be filled up at the expense of other ports buffers. The assumption is that
the partition is signifying a system failure situation (bad connection/cable/station), thus dropping
packets is a small price to pay vs. the cost of halting the switch due to a buffer full condition.
The Port exits from Partition State, following the end of a successful packet transmission. A
successful packet transmission is defined as no collisions were detected on the first 512 bits of the
transmission.
The port detects a collision on every one of 64 consecutive re-transmit attempts to the same
packet.
The port detects a single collision which occurs for more than 512 bit times.
Transmit defer timer time out, which indicates the transmitting packet is deferred to long.
10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
DM8603
72