DS3181/DS3182/DS3183/DS3184
60
PIN
TYPE
FUNCTION
RDATA[31:0]
Oz
Receive Data [31:0] (tri-state)
This signal is tri-state when global reset is applied.
RDATA[31:0]: This 32-bit data bus is used to transfer cell/packet data to the
ATM/Link layer device. This bus is updated on the rising edge of RSCLK.
In 32-bit mode-
RDATA[31] is the MSB and RDATA[0] is the LSB.
In UTOPIA L2 or POS-PHY L2 modes, RDATA[31:0] are driven when one of
the ports is selected for data transfer, and tri-stated when
REN is deasserted,
none of the ports is selected or data path reset is active.
In UTOPIA L3 or POS-PHY L3 modes RDATA[31:0] are driven.
In 16-bit mode-
RDATA[15] is the MSB, RDATA[0] is the LSB, and RDATA[31:16] are not
used.
In UTOPIA L2 or POS-PHY L2 modes, RDATA[15:0] are driven when one of
the ports is selected for data transfer, and tri-stated when
REN is deasserted,
none of the ports is selected or data path reset is active. RDATA[31:16] are
tri-stated.
In UTOPIA L3 or POS-PHY L3 modes, RDATA[31:0] are driven.
In 8-bit mode (reset default)-
RDATA[7] is the MSB, RDATA[0] is the LSB, and RDATA[31:8] are not used.
In UTOPIA L2 (reset default) or POS-PHY L2 modes, RDATA[7:0] are driven
when one of the ports is selected for data transfer, and tri-stated when
REN
is deasserted, none of the ports is selected or data path reset is applied.
RDATA[31:8] are tri-stated.
In UTOPIA L3 or POS-PHY L3 modes, RDATA[31:0] are driven.
RPRTY
Oz
Receive Parity (tri-state)
RPRTY: This signal indicates the parity on the data bus when parity generation is
enabled. This option programmable. RPRTY is held low if parity generation is
disabled. This signal is updated on the rising edge of RSCLK.
In UTOPIA L2 (reset default) or POS-PHY L2 modes, this signal is driven when one
of the ports is selected for data transfer, and tri-stated when
REN is deasserted,
none of the ports is selected or data path reset is active.
In UTOPIA L3 or POS-PHY L3 modes this signal is driven.
REN
I
Receive Enable (active low)
REN: This signal is used by the ATM/Link device to control the transfer of cell/packet
data on the RDATA bus. If
REN is high, no transfer occurs. If REN is low, a transfer
occurs. This signal can be sampled on the rising edge of RSCLK.
RDXA[1] /
RPXA /
RSX
Oz
Receive Direct Cell/Packet Available [1] / Polled Cell/Packet Available / Start of
Transfer (tri-state)
This signal is tri-state when global reset is applied.
RDXA[1]: This signal is active in UTOPIA L2, Utopia L3 or POS-PHY L2 modes
when direct status mode is selected. It is used to indicate when port 1 can send data
to the ATM/Link layer device. This signal is updated on the rising edge of RSCLK.
In UTOPIA L2 or UTOPIA L3 modes, RDXA goes high when the port 1 FIFO has
more than a programmable number of ATM cells ready for transfer ("almost empty"
level). RDXA goes low when the associated port does not have a complete ATM cell
ready for transfer.
In POS-PHY L2 mode, RDXA goes high when the port 1 FIFO contains more data
than the "almost empty" level or has an end of packet ready for transfer. RDXA goes
low when the associated port does not have an end of packet ready for transfer and
is "almost empty".
RPXA: (Reset default) This signal is active in UTOPIA L2, UTOPIA L3 or POS-PHY
L2 modes when polled status mode is selected. It is used to indicate when the polled
port, as selected by RADR[4:0], can send data to the ATM/Link layer device. This
signal is updated on the rising edge of RSCLK.