P R E L I M I N A R Y

 

 

AMD

 

 

 

 

 

 

 

 

 

 

 

 

 

In addition, the USER5/IRQ4 pin may be used to produce interrupts

 

 

 

 

to the 80188 embedded controller. This capability is controlled by

 

 

 

 

the ENXCHBSY bit of TCR28 and the CHBSYCU bit of TIR5 and

 

 

 

 

operates independently of the bits mentioned above.

 

 

 

 

The control of the function of the USER5/IRQ4 pin is described in

 

 

 

 

the Multi-Function Pin section.

 

 

 

4–3

U1INTCNT

00b

USER1 Interrupt control bits. The USER1/IRQ12 pin can be used

 

 

 

 

to signal an interrupt to the 80188 embedded controller. The

 

 

 

 

U1INTCNT bits have the following interpretation and operate inde-

 

 

 

 

pendently of the operating mode of the Am79C930 device (i.e.,

 

 

 

 

the U1INTCNT bits operate in both PCMCIA and ISA Plug and

 

 

 

 

Play modes.):

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U1INT Bit

 

 

 

 

 

 

U1INTCNT

 

USER1 Pin

(TCR11[3])

 

 

 

 

 

TCR7[4:3]

 

Event

Result

 

 

 

 

 

 

 

 

 

 

 

 

 

 

00

 

X

0 => interrupt

 

 

 

 

 

 

 

 

 

disabled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

01

 

rising edge

1 => interrupt

 

 

 

 

 

 

 

 

 

signaled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

 

falling edge

1 => interrupt

 

 

 

 

 

 

 

 

 

signaled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11

 

rising or

1 => interrupt

 

 

 

 

 

 

 

 

falling edge

signaled

 

 

 

 

 

 

 

 

 

 

 

 

 

Note that the USER1 pin function has no effect on the use of the

 

 

 

 

USER1/IRQ12 pin as an interrupt signaling pin. If the

 

 

 

 

USER1/IRQ12 pin is to be used as a 80188 controller interrupt

 

 

 

 

source in the ISA Plug and Play mode, then it is imperative that the

 

 

 

 

ISA Plug and Play resource data structure loaded into the accom-

 

 

 

 

panying flash device as part of the Am79C930 device based design

 

 

 

 

should not include IRQ12 as a choice of IRQ level for possible se-

 

 

 

 

lection by the ISA Plug and Play configuration software. When this

 

 

 

 

procedure is followed, then the system designer can be assured

 

 

 

 

that the IRQ12 function will not be used by the Am79C930 device,

 

 

 

 

and therefore, the USER1/IRQ12 pin will remain in the high-imped-

 

 

 

 

ance state and will be available for connection to an interrupt gener-

 

 

 

 

ating source in the design.

 

 

 

2

TXCMDT

0

 

TXCMD Data. The value written to the TXCMDT bit is used in some

 

 

 

 

modes to determine the output value of the TXCMD/LA21 pin.

 

 

 

 

Reads from TXCMDT always return the current value of the

 

 

 

 

TXCMD/LA21 pin.

 

 

 

 

 

 

 

 

The control of the function of the TXCMD/LA21 pin is described in

 

 

 

 

the Multi-Function Pin section.

 

 

 

1

ANTSLTLD

1

 

ANTSLTL Data. The value that is written to this bit will be driven out

 

 

 

 

to the ANTSLT pin of the Am79C930 device when the ANTSLTLFN

 

 

 

 

bit of TCR30 has been set to a 1 and the ANTSLTLEN bit of TCR15

 

 

 

 

has also been set to a 1 and the PCMCIA pin is set to 1. The value

 

 

 

 

that is read from this bit represents the current value of the ANTSLT

 

 

 

 

pin of the Am79C930 device.

 

 

 

 

 

 

 

A complete description of the control of the function of the ANTSLT

 

 

 

 

pin is described in the Multi-Function Pin section.

0

TXDATALD

1

 

TXDATAL Data. The value that is written to this bit will be driven out

 

 

 

 

to the TXDATA pin of the Am79C930 device when the TXDATALFN

 

 

 

 

bit of TCR30 has been set to a 1 and the TXDATALEN bit of TCR15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Am79C930

 

109

 

Page 109
Image 109
AMD manual U1INTCNT, Txcmdt, Antsltld, Txdatald, Am79C930 109