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NXP Semiconductors
PNX15xx/952x Series
Volume 1 of 1
Chapter 23: LAN100 — Ethernet Media Access Controller
PNX15XX_PNX952X_SER_N_4
NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 4.0 — 03 December 2007
23-678
Table 2: LAN100 Registers
Bit
Symbol
Acces
s
Value
Description
MII Interface Registers
Offset 0x07 2000
MAC Congurationuration Register 1 (MAC1)
31:16
-
0
Unused
15
SOFT_RESET
R/W
1
Setting this bit puts all modules within the MII Interface into the reset
state. MII Interface registers are not reset. It has no effect upon
LAN100 components other than the MII Interface. Clearing this bit
restores the MII Interface to operation. Its default value is 1 (reset).
14
SIMULATION_RESET
R/W
0
Setting this bit will reset the random number generator within the
Transmit function of the MII Interface.
13:12
-
0
Unused
11
RESET_PEMCS/Rx
R/W
0
Setting this bit puts the MAC Control Sublayer / Rx domain logic into
the reset state.
10
RESET_PERFUN
R/W
0
Setting this bit puts the Receive Function logic in the reset state.
9
RESET_PEMCS_Tx
R/W
0
Setting this bit puts the MAC Control Sublayer / Tx domain logic in
the reset state.
8
RESET_PETFUN
R/W
0
Setting this bit puts the MII Interface Transmit function logic in the
reset state.
7:5
-
0
Unused
4
LOOPBACK
R/W
0
Setting this bit causes the MAC Transmit interface to be looped
backed to the MAC Receive interface. Clearing this bit results in
normal operation.
3
TX_FLOW_CONTROL
R/W
0
When set, PAUSE Flow Control frames are allowed to be
transmitted. When cleared, Flow Control frames are blocked.
2
RX_FLOW_CONTROL
R/W
0
When set, the MAC acts upon received PAUSE Flow Control
frames. When cleared, received PAUSE Flow Control frames are
ignored.
1
PASS_ALL_RECEIVE_
FRAMES
R/W
0
When set, the MAC will indicate PASS CURRENT RECEIVE
FRAME for all frames regardless of type (normal vs. Control).
When cleared, the MAC deasserts PASS CURRENT RECEIVE
FRAME for valid Control frames.
0
RECEIVE_ENABLE
R/W
0
Set this bit to enable receiving frames. Internally, the MAC
synchronizes this control bit to the incoming receive stream and
outputs SYNCHRONIZED RECEIVE ENABLE, to be used by the
host system to qualify receive frames.
Offset 0x07 2004
MAC Conguration Register 2 (MAC2)
31:16
-
0
Unused
14
EXCESS_DEFER
R/W
0
When set, the MAC will defer to carrier indenitely as per the
Standard
[1]. When cleared, the MAC will abort when the excessive
deferral limit is reached, and will provide feedback to the host
system.
13
BACK_PRESSURE
R/W
0
When set, the MAC after incidentally causing a collision during back
pressure will immediately retransmit without backoff, reducing the
chance of further collisions and ensuring transmit packets get sent.