Intel 21555 User Manual

Page 189

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21555 Non-Transparent PCI-to-PCI Bridge User Manual

189

List of Registers

Table 124. CompactPCI Hot

-

Swap Capability Identifier and Next Pointer Register

Bit

Name

R/W

Description

7:0

HS ECP ID

R

Enhanced capabilities ID. Reads only as 06h to indicate that these are
CompactPCI Hot

-

Swap registers.

7:0

HS NXT
PTR

R

Pointer to next set of ECP registers. Reads only as 0 to indicate that
these are the last ECP registers in this list.

Table 125. CompactPCI Hot

-

Swap Control Register (Sheet 1 of 2)

Primary byte offset: EF:EEh

Secondary byte offset: EF:EEh

Bit

Name

R/W

Description

0

Reserved

R

Reserved. Read only as 0.

1

ENUM_MASK

R/W

ENUM# Interrupt Mask.

When 0, the 21555 asserts p_enum_l when an insertion or removal
event occurs.

When 1, the 21555 does not assert p_enum_l.

Reset value is 0

2

Reserved

R

Reserved. Read only as 0.

3

LED On/Off (LOO)

R/W

LED On/Off (LOO) Control. Allows software control of the l_stat pin and
therefore the state of the LED.

When 0, the 21555 tristates l_stat. When REM STAT is low, the
LED is off when the ejector handle is closed and on when the
ejector handle is open. When REM STAT is high, l_stat is not
tristated but continues to be driven by the 21555 (LED is off).

When 1, the 21555 drives l_stat high and the LED is forced on.

Reset value is 0

Offsets

HS ECP ID

HS Next Pointer

Primary byte

ECh

EDh

Secondary byte

ECh

EDh

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