AMD Am79C930 - Manual (Page 35)

P R E L I M I N A R Y AMD
35 Am79C930
Note that a read of the USERDT[0] bit (TIR29[0]) will al-
ways give the current USER0/RFRSH pin value, regard-
less of pin configuration setting. Pin 91: USER1/IRQ12/EXTCTS/EXINT188
The USER1/IRQ12 pin may be configured for input
operation, output operation, or ISA IRQ12 operation ac-
cording to the following table:
USER1/ USER1/
PCMCIA USER1EN IRQ Select IRQ Type IRQ12 IRQ12
Pin TCR14[1] PnPx70 PnPx71 Pin Direction Pin Data
0 X Ch 2h O IRQ12
0 X Ch 1h OD IRQ12
0 0
≠
Ch X I NA
0 1
≠
Ch X O TIR29[1]
1 0 X X I NA
1 1 X X O TIR29[1]
Note that a read of the USERDT[1] bit (TIR29[1]) will al-
ways give the current USER1/IRQ12 pin value, regard-
less of pin configuration setting.
In addition to the functionality listed above, the
USER1/IRQ12/EXTCTS/EXINT188 pin may be used to
enable the internal TX state machine. This capability is
controlled by the CTSEN bit of TCR7 and operates inde-
pendently of the table above and independently of the
U1INTCNT bits of TCR7. When the CTSEN bit of TCR7
is set to 1, then the value of the USER1/IRQ12/
EXTCTS/EXINT188 pin will be ANDed with the value of
the TXS bit of TIR8. The output of the AND gate will
then be used to determine the start of the TX state
machine. In this way, an external signal, through the
USER1/IRQ12/EXTCTS/EXINT188 input, can be used
to control the start of the TX state machine, provided that
Am79C930 device firmware has enabled the operation
by setting the TXS bit of TIR8.
In addition to the functionality listed above, the
USER1/IRQ12/EXTCTS/EXINT188 pin may be used to
produce interrupts to the 80188 embedded controller.
This capability is controlled by the U1INTCNT bits of
TCR7 and operates independently of the bits in the
table above and independently of the CTSEN bit of
TCR7.Interrupts that are routed through the
USER1/IRQ12/EXTCTS/EXINT188 pin are indicated in
the U1INT bit of TCR11. The following table lists the pro-
gramming options for using the USER1/IRQ12/
EXTCTS/EXINT188 pin as a source of external interrupt
to the 80188 controller.
U1INTCNT USER1 Pin U1INT Bit
TCR7[4:3] Event Result (TCR11[3])
00 X 0 => interrupt disabled reset default condition
01 rising edge 1 => interrupt signalled
10 falling edge 1 => interrupt signalled
11 rising or falling edge 1 => interrupt signalled
Pin 92: USER7/IRQ11
The USER7/IRQ11 pin may be configured for input op-
eration, output operation, or ISA IRQ11 operation ac-
cording to the following table:
Note that a read of the USER7DL bit (TIR29[7]) will al-
ways give the current USER7/IRQ11 pin value, regard-
less of pin configuration setting.
USER7DL (TIR29[7]) gives the current value of the
USER7/IRQ11 pin.
USER7/ USER7/
PCMCIA USER7FN USER7EN IRQ Select IRQ Type IRQ11 IRQ11
Pin TC30[7] TCR14[7] PnPx70 PnPx71 Pin Direction Pin Data
0 0 X Bh 2h O IRQ11
0 0 X Bh 1h OD IRQ11
0 0 X ≠ Bh X I NA
0 1 X X X I NA
1 0 0 X X I NA
1 0 1 X X O TIR29[7]
1 1 X X X I NA