P R E L I M I N A R Y

AMD

 

 

ENXCHBSY bit of TCR28 and the CHBSYU bit of TIR5 and operates independently of the bits in the table below.

In addition to the functionality listed above, the USER5/IRQ4/EXTCHBSY pin may be used as the source for CCA information, instead of relying on the in- ternal CCA logic of the Am79C930 device. When using the external CCA information, CCA information from the internal logic will be unavailable. External CCA informa- tion will appear in the same register bit locations as in- ternal CCA information, when enabled, so a change from internal source to external source will be transpar- ent to firmware (excepting the necessary change in the ENXCHBSY bit value).

This source of CCA information is controlled by the ENXCHBSY bit of TCR28. When the ENXCHBSY bit of TCR28 is set to a 1, then the value of the USER5/IRQ4/EXTCHBSY pin will be fed directly to the CHBSYC bit of TIR4, CHBSY bit of TIR26 and the BCF bit of TIR5. If the CHBSYC interrupt is unmasked, it will produce an interrupt to the 80188 embedded controller. If the BCF interrupt is unmasked, it will produce an inter- rupt to the 80188 embedded controller. Note that setting the ENXCHBSY bit of TCR28 to a 1 will cause the USER5/IRQ4/EXTCHBYS pin to function as an input, regardless of the settings of the other control bits listed.

 

 

 

 

 

 

USER5/

USER5/

PCMCIA

ENXCHBSY

USER5FN

USER5EN

IRQ Select

IRQ Type

IRQ4

IRQ4

Pin

TCR28[5]

TCR7[5]

TCR15[2]

PnPx70

PnPx71

Direction

Pin Data

 

 

 

 

 

 

 

 

0

1

X

X

X

X

I

TIR11[5]

 

 

 

 

 

 

 

 

0

0

0

X

4h

2h

O

IRQ4

 

 

 

 

 

 

 

 

0

0

0

X

4h

1h

OD

IRQ4

 

 

 

 

 

 

 

 

0

0

0

0

4h

X

I

TIR11[5]

 

 

 

 

 

 

 

 

0

0

0

1

4h

X

O

TIR11[5]

 

 

 

 

 

 

 

 

0

0

1

0

X

X

I

TIR11[5]

 

 

 

 

 

 

 

 

0

0

1

1

X

X

O

TIR11[5]

 

 

 

 

 

 

 

 

1

1

X

X

X

X

I

TIR11[5]

 

 

 

 

 

 

 

 

1

0

X

0

X

X

I

TIR11[5]

 

 

 

 

 

 

 

 

1

0

X

1

X

X

O

TIR11[5]

Pin 98: ACT

The ACT pin may be configured for input or output op- eration. The output drive may be programmed for totem pole or open drain operation. ACT pin configuration is accomplished according to the following table:

Note that a read of the ACT bit (TIR0[6]) will always give the current ACT pin value, regardless of pin configuration setting.

ACTEN

ACT

ACTDR

ACT Pin

ACT Pin

 

TCR15[1]

TIR0[6]

TCR27[3]

Direction

Value

 

 

 

 

 

 

 

0

X

X

I

NA

 

1

0

0

OD

float

reset default condition

 

 

 

 

 

 

1

1

0

OD

LOW

 

 

 

 

 

 

 

1

0

1

O

HIGH

 

 

 

 

 

 

 

1

1

1

O

LOW

 

 

 

 

 

 

 

Pin 100: LNK

The LNK pin may be configured for input or output op- eration. The output drive may be programmed for totem pole or open drain operation. LNK pin configuration is accomplished according to the following table:

Note that a read of the LNK bit (TIR0[7]) will always give the current LNK pin value, regardless of pin configuration setting.

LNKEN

LNK

LNKDR

LNK Pin

LNK Pin

 

TCR13[7]

TIR0[7]

TCR27[4]

Direction

 

Value

 

 

 

 

 

 

 

 

0

X

X

I

 

NA

 

1

0

0

OD

 

float

reset default condition

 

 

 

 

 

 

 

1

1

0

OD

 

LOW

 

1

0

1

O

 

HIGH

 

 

 

 

 

 

 

 

1

1

1

O

 

LOW

 

 

 

 

 

 

 

 

 

 

 

Am79C930

 

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Image 37
AMD Am79C930 manual Pin 98 ACT, Pin 100 LNK