MT90883 Zarlink Semiconductor, MT90883 Datasheet - Page 15

• Manufacturer Part Number: MT90883
• Description: (MT90880 - MT90883) TDM to Packet Processors
• Manufacturer: Zarlink Semiconductor

3.3.2
The RMII is a low pin count MII interface. It has no defined standard, but the RMII Consortium publishes details
(reference 3, Table 2). The MT90880 RMII Interface shares the same pins as the MII interface with the
exception of the REF_CLK.
The RMII comprises a low pin count Reduced Media Independent Interface
use between Ethernet PHYs and Switch ASICs. Under IEEE 802.3u [2] an MII, comprised of 16 pins for data
and control, is defined. In devices incorporating many MACs or PHY interfaces such as switches, the number of
pins can add significant cost as the port counts increase. The purpose of this interface is to provide a low cost
alternative to the IEEE 802.3u [2] MII. Architecturally, the RMII specification provides for an additional
reconciliation layer on either side of the MII but can be implemented in the absence of an MII. The management
interface (MDIO/MDC) is assumed to be identical to that defined in IEEE 802.3u [2].
All RMII signals are 5 V tolerant.
All RMII outputs are high impedance while S_RST is low.
m0_txclk
m0_rxd[3:0]
m0_rxdv
m0_rxclk
m0_rxer
m0_crs
m0_col
MII Port B
m_mint1
m1_txd[3:0]
m1_txen
m1_txclk
m1_rxd[3:0]
m1_rxdv
m1_rxclk
m1_rxer
m1_crs
m1_col
Signal
RMII Interfaces
O U
O U
I/O
I U
I U
I D
I U
I D
I D
I D
I D
I U
I U
I U
I D
I U
I D
I D
AC9
AE7
AB9
AF8 [3], AE8 [2], AE9 [1], AD9 [0]
AF7
AB10
AD8
AE11
AC11 [3], AE10 [2], AF10 [1], AD11
[0]
AD10
AB12
AF12 [3], AD13 [2], AE13 [1], AF13
[0]
AE12
AC13
AD12
AC12
AF11
Table 6 - MII Interfaces (continued)
Package Balls
Zarlink Semiconductor Inc.
MT90880/1/2/3
15
Transmit clock
Receive data
Receive data valid
Receive clock
Receive error
Carrier sense
Collision detect
Transmit data
Transmit enable
Transmit clock
Receive data
Receive data valid
Receive clock
Receive error
Carrier sense
Collision detect
MII management interrupt for port B
TM
(RMII
Description
TM
)
specification intended for
Data Sheet