82595FX Datasheet, PDF (20/54 Pages) Intel Corporation – ISA BUS HIGH INTEGRATION ETHERNET CONTROLLER

82595FX
4 6 Boot EPROM FLASH Interface
The Boot EPROM FLASH of an 82595FX solution is
read from or written to (FLASH only) whenever the
host CPU performs a Read or a Write operation to a
memory location that is within the Boot EPROM
FLASH mapping window This window is program-
mable throughout the ISA PROM address range
(C8000–DFFFF) by configuring the 82595FX Boot
EPROM Decode Window register (Bank 1 Register
2 bits 4–6) The 82595FX asserts the BOOTCS
signal when it decodes a valid access Up to 1
MBytes of FLASH can be addressed by the
82595FX
5 0 COMMAND AND STATUS
INTERFACE
The format for the 82595FX Command Register is
shown in Figure 5-1 The Command Register resides
in Register 0 of each of the three IO Banks of the
82595FX and can be accessed in any of these
banks The Command Register is accessed by writ-
ing to or reading from the IO address for Register 0
5 1 Command OP Code Field
Bits 0 through 4 of the Command Register comprise
the Command OP Code field A command is issued
to the 82595FX by writing it into the Command OP
Code field A command can be issued to the
82595FX at any time however in certain cases the
command may be ignored (for example issuing a
Transmit command while a Transmit is already in
progress) In these cases the command is not per-
formed and no interrupt will result from it
The Command OP Code field can also be read In
this case it will indicate an execution status event
other than TRANSMIT DONE (TDR Done DIAG-
NOSE Done MC-SETUP Done DUMP Done INIT
Done and POWER-UP) has been completed This
field is valid only when the EXEC INT bit (Bank 0
Reg 1 Bit 3) is set
5 2 ABORT (Bit 5)
This bit indicates if an execution command other
than TRANSMIT was aborted while in progress This
bit provides status information only It should be writ-
ten to a 0 whenever the Command Register is writ-
ten to
5 3 Pointer Field (Bits 6 and 7)
The Pointer field controls which 82595FX IO register
bank is currently to be accessed (Bank 0 Bank 1 or
Bank 2) Writing a 00 b to the Pointer field selects
Bank 0 01 b for Bank 1 and 10 b for Bank 2 The
Pointer field is valid only when the SWITCH BANK
(0h) command is issued This field will be ignored for
any other command The 82595FX will continue to
operate in a current bank until a different bank is
selected Upon power up of the device or Reset the
82595FX will default to Bank 0
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