12 bank 1 - base address register, 13 bank 1 - individual address registers, Bank 1 - base address register – SMSC LAN91C111 User Manual

Page 55: Bank 1 - individual address registers, Datasheet

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10/100 Non-PCI Ethernet Single Chip MAC + PHY

Datasheet

SMSC LAN91C111 REV C

55

Revision 1.91 (08-18-08)

DATASHEET

8.12

Bank 1 - Base Address Register

This register holds the I/O address decode option chosen for the LAN91C111. It is part of the EEPROM
saved setup and is not usually modified during run-time.

A15 - A13 and A9 - A5 - These bits are compared against the I/O address on the bus to determine
the IOBASE for the LAN91C111‘s registers. The 64k I/O space is fully decoded by the LAN91C111
down to a 16 location space, therefore the unspecified address lines A4, A10, A11 and A12 must be
all zeros.

All bits in this register are loaded from the serial EEPROM. The I/O base decode defaults to 300h
(namely, the high byte defaults to 18h).

Reserved – Reserved bits.

Below chart shows the decoding of I/O Base Address 300h:

8.13

Bank 1 - Individual Address Registers

These registers are loaded starting at word location 20h of the EEPROM upon hardware reset or
EEPROM reload. The registers can be modified by the software driver, but a STORE operation will not
modify the EEPROM Individual Address contents. Bit 0 of Individual Address 0 register corresponds
to the first bit of the address on the cable.

OFFSET

NAME

TYPE

SYMBOL

2

BASE ADDRESS

REGISTER

READ/WRITE

BAR

HIGH

BYTE

A15

A14

A13

A9

A8

A7

A6

A5

0

0

0

1

1

0

0

0

LOW

BYTE

Reserved

Reserved

0

0

0

0

0

0

0

1

A15

A14

A13

A12

A11

A10

A9

A8

A7

A6

A5

A4

A3

A2

A1

A0

0

0

0

0

0

0

1

1

0

0

0

0

0

0

0

0

OFFSET

NAME

TYPE

SYMBOL

4

THROUG

H 9

INDIVIDUAL ADDRESS

REGISTERS

READ/WRITE

IAR

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