
Agere Systems Inc.
129
Data Sheet
July 2001
T8302 Internet Protocol Telephone
Advanced RISC Machine (
ARM
)
11 10/100 2-Port Repeater and Backplane Segment Controller
(continued)
11.4 Repeater Slice Interfaces
11.4.1 Repeater Slice
ARM
Interface
Table 109. Repeater Slice
ARM
Interface
Note: For a fuller explanation and timing diagrams consult:
http://www.arm.com/Documentation/UserMans/
AMBA
/pdf/
AMBA
vD.pdf
11.4.2 Repeater Slice Interface
Signal
P_CLK
P_WRITE
Type
I
I
Description
Peripheral clock.
ARM
peripheral bus clock.
ARM
read/write. Indicates which direction the data bus is in, for the current register. This
signal should be driven high when reading a register and low when writing a register.
ARM
ready (active-low). This signal indicates that the repeater has latched data during a
write cycle and has placed valid data onto the bus during a read cycle.
Reset (active-high). Assumed to be asynchronous. Used to reset repeater core and reg-
isters.
ARM
address bus.
The address bus is used by the
ARM
to indicate which register is
being read or written.
ARM
write data bus. This data bus is used by the
ARM
to write to registers.
ARM
read data bus. This data bus is used by the
ARM
to read from registers.
P_WAIT
O
P_RST
I
P_A
I
P_WD
P_RD
I
O
Table 110. Repeater Slice Interface
Signal
Type
I
Description
RXD(1, 0)[3:0]
Receive data.
In 10 Mbits/s mode,
RXD[0]
is the serial receive data from the PHY and is clocked in
on the rising edge of
RX_CLK
. If
RXDVAV
is set high in the
port configuration reg-
ister 0
(see Table 117 on page 136)
,
RX_DV
and
CRS
must be asserted for data to
be accepted. If
RXDVAV
is set low in the
port configuration register 0
, only
CRS
must be asserted for data to be accepted.
RXD[3:1]
is ignored in 10 Mbits/s mode.
In 100 Mbits/s mode,
RXD[3:0]
represent the 4-bit data being received by the PHY.
RX_DV
must be asserted for data to be accepted.
RXD
is clocked into the repeater
slice with the rising edge of
RX_CLK
.
RXD[0]
is the least significant bit of the nibble.
Receive data valid.
RX_DV(1,0)
I
In 10 Mbits/s mode,
RX_DV
is ignored if
RXDVAV
in the
port configuration
register 0
(see Table 117 on page 136)
is set low.
CRS
represents the packet enve-
lope. If RXDVAV is set high, the repeater uses it to qualify
RXD
.
In 100 Mbits/s mode,
RX_DV
indicates that
RXD[3:0]
contain recovered and
decoded nibbles of data from the PHY.
RX_DV
must transition synchronously with
respect to the
RX_CLK
.
RX_DV
must remain asserted continuously from the first
recovered nibble of the frame through the final recovered nibble and must be negated
prior to the first
RX_CLK
that follows the final nibble.
RX_DV
must encompass the
frame, starting no later than the start frame delimiter and excluding any end-of-frame
delimiter.