Control/status registers, 1 lan (ethernet) control/status registers – Intel GD82559ER User Manual

Page 63

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Datasheet

57

Networking Silicon — GD82559ER

8.

Control/Status Registers

8.1

LAN (Ethernet) Control/Status Registers

The 82559ER’s Control/Status Register (CSR) is illustrated in the figure below.

NOTE: In

Figure 23

above, SCB is defined as the System Control Block of the 82559ER, and PMDR is defined

as the Power Management Driver Register.

SCB Status Word:

The 82559ER places the status of its Command and Receive units
and interrupt indications in this register for the CPU to read.

SCB Command Word:

The CPU places commands for the Command and Receive units in
this register. Interrupts are also acknowledged in this register.

SCB General Pointer:

The SCB General Pointer register points to various data structures
in main memory depending on the current SCB Command word.

PORT Interface:

The PORT interface allows the CPU to reset the 82559ER, force the
82559ER to dump information to main memory, or perform an
internal self test.

Flash Control Register:

The Flash Control register allows the CPU to enable writes to an
external Flash.

EEPROM Control Register: The EEPROM Control register allows the CPU to read and write to

an external EEPROM.

D31 Upper Word D16

D15 Lower Word D0

Offset

SCB Command Word

SCB Status Word

00H

System Control Block General Pointer

04H

PORT

08H

EEPROM Control Register

Flash Control Register

0CH

Management Data Interface (MDI) Control Register

10H

Receive Direct Memory Access Byte Count

14H

PMDR

Flow Control Register

Early Receive Int

18H

Reserved

General Status

General Control

1CH

Reserved

20H

Reserved

24H

Reserved

28H

Reserved

2CH

Reserved

30H

Reserved

34H

Reserved

38H

Reserved

3CH

Figure 23. 82559ER Control/Status Register

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