
DS33R41 Inverse-Multiplexing Ethernet Mapper with Quad Integrated T1/E1/J1 Transceivers
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NAME
PIN
TYPE
FUNCTION
TXD[0]
TXD[1]
TXD[2]
TXD[3]
L20
M19
M18
M20
O
Transmit Data 0 through 3(MII).
TXD [3:0] is presented synchronously
with the rising edge of TX_CLK. TXD [0] is the least significant bit of the
data. When TX_EN is low the data on TXD should be ignored.
Transmit Data 0 through 1(RMII).
Two bits of data TXD [1:0] presented
synchronously with the rising edge of REF_CLK.
TX_EN
L19
O
Transmit Enable (MII).
This pin is asserted high when data TXD [3:0] is
being provided by the DS33R41. The signal is deasserted prior to the first
nibble of the next frame. This signal is synchronous with the rising edge
TX_CLK. It is asserted with the first bit of the preamble.
Transmit Enable (RMII).
When this signal is asserted, the data on TXD
[1:0] is valid. This signal is synchronous to the REF_CLK.
REF_CLK
C20
I
Reference Clock (RMII and MII).
When in RMII mode, all signals from
the PHY are synchronous to this clock input for both transmit and receive.
This required clock can be up to 50MHz and should have
±100ppm
accuracy.
When in MII mode in DCE operation, the DS33R41 uses this input to
generate the RX_CLK and TX_CLK outputs as required for the Ethernet
PHY interface. When the MII interface is used with DTE operation, this
clock is not required and should be tied low.
In DCE and RMII modes, this input must have a stable clock input before
setting the RST pin high for normal operation.
REF_CLKO
G19
O
Reference Clock Output (RMII and MII).
A derived clock output up to
50MHz, generated by internal division of the SYSCLKI signal. Frequency
accuracy of the REF_CLKO signal will be proportional to the accuracy of
the user-supplied SYSCLKI signal. See Section
9.1.2 for more
information.
DCEDTES
L17
I
DCE or DTE Selection.
The user must set this pin high for DCE Mode
selection or low for DTE Mode. In DCE Mode, the DS33R41 MAC port
can be directly connected to another MAC. In DCE Mode, the Transmit
clock (TX_CLK) and Receive clock (RX_CLK) are output by the
DS33R41. Note that there is no software bit selection of DCEDTES. Note
that DCE Mode is only relevant when the MAC interface is in MII mode.
RMIIMIIS
K13
I
RMII or MII Selection.
Set high to configure the MAC for RMII interfacing.
Set low for MII interfacing.
PHY MANAGEMENT BUS
MDC
E20
O
Management Data Clock (MII).
Clocks management data between the
PHY and DS33R41. The clock is derived from the SYSCLKI, with a
maximum frequency is 1.67MHz. The user must leave this pin
unconnected in the DCE Mode.
MDIO
F20
IO
MII Management data IO (MII).
Data path for control information between
the PHY and DS33R41. When not used, pull to logic high externally
through a 10k
Ω resistor. The MDC and MDIO pins are used to write or
read up to 32 Control and Status Registers in 32 PHY Controllers. This
port can also be used to initiate Auto-Negotiation for the PHY. The user
must leave this pin unconnected in the DCE Mode.
SDRAM CONTROLLER
SCAS
R14
O
SDRAM Column Address Strobe.
Active low output, used to latch the
column address on the rising edge of SDCLKO. It is used with commands
for Bank Activate, Precharge, and Mode Register Write.
SRAS
P15
O
SDRAM Row Address Strobe.
Active low output, used to latch the row
address on rising edge of SDCLKO. It is used with commands for Bank
Activate, Precharge, and Mode Register Write.
SDCS
R15
O
SDRAM Chip Select.
Active low output enables SDRAM access.