DP83858VF datasheet(9/37 Pages) NSC

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2.4 Miscellaneous

Signal Name

Type

Active

Pin Description

LCK

—

Local Clock: Must be 25 MHz

± 50ppm. Used for TX data transfer to Physical Layer

devices, TX Bus data transfers and DP83858 internal state machines.

RID[4:0]

—

Repeater Identiﬁcation Number: Provides the unique vector for the IR_VECT[4:0]

signals used in Inter Repeater bus arbitration. These bit are also used to uniquely iden-

tify this chip for serial register accesses. The RID value is latched when reset is de-

asserted.

Note: The arbiter cannot use the value 1Fh as its arbitration vector. This is the

IR_VECT[4:0] bus idle state, therefore RID[4:0] must never be set to this value.

/RST

low

Reset: The chip is reset when this signal is asserted low.

GRDIO

I/O/Z, L

—

Gated Register Data Input/Output: This I/O is a gated version of RDIO. When the

“phy_access” bit in the CONFIG register is set high, the RDIO signal is passed through

to GRDIO for accessing the physical layer chips.

Note: Input buffer has a weak pull-up.

BRDC

O, L

—

Buffered Register Data Clock: Buffered version of RDC. Allows more devices to be

chained on the MII serial bus.

RDIR

O, L

high

RDIO signal.

= RDIO data ﬂows into the DP83858

= RDIO data ﬂows out of the DP83858

Defaults to 0 when no register access is present.

PART[5:0]

O, L

—

Partition: Used to indicate each port's Jabber and Partition status. PART[3:0] cycle

through each port number (0-11) continuously. PART[4] indicates the Partition status

for each port (1 = Port Partitioned). PART[5] indicates the Jabber status for each port

(1 = Port Jabbering). These pins are intended to be decoded to drive LEDs.

RID_ER

O, L

high

Repeater ID Error: This pin is asserted under the conditions which set the RID_error

bit in the DEVICEID register.

RSM[3]

/RXECONFIG

I/O, L

—

Repeater State Machine Output/ RXE Polarity: This pin is an input during reset and

it is used to latch the desired polarity of RXE[7:0] signals.

When this pin is pulled high or it is unconnected, then the RXE signals become active

high. However, if this signal is pulled low, then the RXE signals become active low.

In all other non-reset times, this pin reﬂects the output of the Repeater State Machine.

RSM[3]

RSM[2:0]

I/O, L O, L

—

Test Outputs indicating the state of the Repeater State Machine.

RSM[3:0]

State

idle

collision

one port left

repeat

noise

Other states are undeﬁned.

MODE[1:0]

—

Mode Inputs: The 100RIC8 may be conﬁgured in the following modes:

MODE[1:0]

Operation

0,0

No special modes selected

1,0

Test mode

0,1

Test mode

1,1

Preamble regeneration (T4) mode

Note: A table showing pin type designation is given in section 2.5

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