
DM9331
100 Mbps Twisted Pair/Fiber Ethernet Media Converter Chip
10
Preliminary
Version: DM9331-DS-P02
September 21, 2001
Functional Description
The DM9331 Fast Ethernet single-chip transceiver,
providing the functionality as specified in IEEE 802.3u,
integrates a complete 100Base-TX module and a complete
100Base-FX module. The DM9331 provides a Media
Converter Interface (MCI) as connection interface.
The DM9331 performs all PCS (Physical Coding Sublayer),
PMA (Physical Media Access), TP-PMD (Twisted Pair
Physical Medium Dependent) sublayer and a PECL
compliant interface for a fiber optic module. Figure 1
shows the major functional blocks implemented in the
DM9331.
Media
Converter
Interface
(MCI)
1
00Base-TX/FX
Transmitter
1
00Base-TX/FX
Receiver
Auto
Negotiation
MII Serial
Management
Interface
Figure 1
MCI Interface
The DM 9331 provides a Media Converter Interface (MCI) .
The purpose of the MCI interface is to provide a simple, easy
to implement connection to another DM9331.
The MCI consists of a 2 bits receive data bus, a two bits
transmit data bus, and control signals to facilitate data
transfers between the two DM9331 chips.
TXD (transmit data) is a two bits of data that are driven
by the reconciliation sublayer synchronously with
respect to OSCIN clock For each OSCIN clock period
which TXEN is asserted, TXD (1:0) are accepted for
transmission by the PHY.
TXEN (transmit enable) input from another DM9331
RXDV signal reconciliation sublayer indicates that data
are being presented on the MCI for transmission on the
physical medium.
RXD (receive data) is a two bits of data that are
sampled by the reconciliation sublayer synchronously
with respect to OSCIN clock. For each OSCIN clock
period which RXDV is asserted, RXD (1:0) are
transferred from the PHY to another DM9331.
RXDV (receive data valid) output to another DM9331
TXEN signal indicates that the DM9331 is data ready.