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Pin 95: user6/irq5/extsdf, Pin 96: user5/irq4/extchbsy – AMD Am79C930 User Manual

Page 36

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AMD

P R E L I M I N A R Y

36

Am79C930

Pin 94: RXC/IRQ10/EXTA2DST

The RXC/IRQ10 pin may be configured for input opera-
tion, output operation, ISA IRQ10 operation, and as an
output providing the RX clock information (whether de-
rived from the RXDATA stream through Am79C930
device DPLL operation or simply rerouted from the
RXCIN input) according to the following table:

Note that a read of the RXCD bit (TIR11[7]) will always
give the current RXC/IRQ10 pin value, regardless of pin
configuration setting.

In addition to the functionality listed above, the RXC/
IRQ10/EXTA2DST pin may be used to control the start
of the A/D conversion process. When the UXA2DST
bit of TCR25 has been set to a 1, then the normal
internal state machine control of the A/D sample and
conversion procedure or a rising edge on the RXC/
IRQ10/EXTA2DST pin will trigger an A/D conversion
procedure. By allowing external control of the start of the
A/D conversion process, the EXTADTST input allows
synchronization of the internal A/D function to an exter-
nal circuit that desires to use the A/D converter.

RXC/

RXC/

PCMCIA

RXCFN

RXCEN

IRQ Select

IRQ Type

IRQ10

IRQ10

Pin

TCR28[7]

TCR15[4]

PnPx70

PnPx71

Pin Direction

Pin Data

0

0

X

Ah

2h

O

IRQ10

0

0

X

Ah

1h

OD

IRQ10

0

0

0

Ah

X

I

TIR11[7]

0

0

1

Ah

X

O

TIR11[7]

0

1

X

X

X

O

RXC

1

0

0

X

X

I

TIR11[7]

1

0

1

X

X

O

TIR11[7]

1

1

X

X

X

O

RXC

Pin 95: USER6/IRQ5/EXTSDF

The USER6/IRQ5/EXTSDF pin may be configured for
input operation, output operation, or ISA IRQ5 operation
according to the following table:

Note that a read of the USER6D bit (TIR11[6]) will al-
ways give the current USER6/IRQ5 pin value, regard-
less of pin configuration setting.

USER6/

USER6/

PCMCIA

ENXSDF

USER6FN

USER6EN

IRQ Select

IRQ Type

IRQ5

IRQ5

Pin

TCR28[6]

TCR7[6]

TCR15[3]

PnPx70

PnPx71

Pin Direction

Pin Data

0

1

X

X

X

X

I

TIR11[6]

0

X

0

X

5h

2h

O

IRQ5

0

X

0

X

5h

1h

OD

IRQ5

0

0

0

0

5h

X

I

TIR11[6]

0

0

0

1

5h

X

O

TIR11[6]

0

0

1

0

X

X

I

TIR11[6]

0

0

1

1

X

X

O

TIR11[6]

1

1

X

X

X

X

I

TIR11[6]

1

0

X

0

X

X

I

TIR11[6]

1

0

X

1

X

X

O

TIR11[6]

In addition to the functionality listed above, the
USER6/IRQ5/EXTSDF pin may be used to enable the
function of the RX state machine within the Am79C930
device. This capability is controlled by the ENXSDF bit
and the ENXCHBSY bit, both of TCR28. When the
ENXSDF bit and the ENXCHBSY bit of TCR28 are both
set to a 1 and either TCR28 bit 4 is set to 0 or an antenna
selection has been made, then the value of the
USER6/IRQ5/EXTSDF pin will be used to enable trans-
fers of RXD data into the RX FIFO, provided the
Am79C930 device firmware has previously enabled the
RX state machine by setting the RXS bit of TIR16. In
addition, the EXTSDF value will be sent to the SDF inter-
rupt bit of TIR5[2]. TIR5[2] will, if unmasked, produce an
interrupt to the 80188 embedded controller.

Note that setting the ENXSDF bit of TCR28 to a 1
will cause the USER6/IRQ5/EXTSDF pin to function as
an input, regardless of other control bit settings.

Pin 96: USER5/IRQ4/EXTCHBSY

The USER5/IRQ4 pin may be configured for input op-
eration, output operation, or ISA IRQ4 operation accord-
ing to the table below.

Note that a read of the USER5D bit (TIR11[5]) will al-
ways give the current USER5/IRQ4/EXTCHBSY pin
value, regardless of pin configuration setting. In addition
to these bits, the USER5/IRQ4/EXTCHBSY pin may
be used to produce interrupts to the 80188 embedded
controller. This capability is controlled by the