![](http://datasheet.mmic.net.cn/390000/SYM53C1010-33_datasheet_16836324/SYM53C1010-33_109.png)
PCI Bus Interface Signals
3-15
3.3.7 SCSI Function A GPIO Signals
Table 3.12
describes the SCSI Function A GPIO Signals group.
INT_DIR
G2
I
N/A
Interrupt Direction.
This input signal indicates whether
internally generated interrupts are presented on INTA/ and
INTB/. If INT_DIR is high, internal interrupts are generated
on both the INTx/ pins and the ALT_INTx pin. If INT_DIR
is low, the internal interrupts are generated only on the
ALT_INTx/ pin. This pin has no effect if either bit 0 or 1 in
STEST1 is set. This pin has a static pull-up.
1. See register 0x4D,
SCSI Test One (STEST1)
in
Chapter 4, "Registers"
for additional information on
these signals.
Table 3.11
Interrupt Signals (Cont.)
Name
1
Bump
Type
Strength
Description
Table 3.12
SCSI Function A GPIO Signals
Name
Bump
Type Strength Description
A_GPIO0_
FETCH/
AB16
I/O
8 mA
SCSI Function A General Purpose I/O pin 0.
This pin is
programmable at power-up, through the MAD7 pin, to serve
as the data signal for the serial EEPROM interface. When
GPIO_0 is not in the process of downloading EEPROM data
it can be used to drive a SCSI Activity LED, if bit 5 in the
General Purpose Pin Control (GPCNTL)
register is set. Or,
it can be used to indicate that the next bus request will be
an opcode fetch if bit 6 in the GPCNTL register is set.
A_GPIO1_
MASTER/
Y16
I/O
8 mA
SCSI Function A General Purpose I/O pin 1.
This pin is
programmable at power-up, through the MAD7 pin, to serve
as the clock signal for the serial EEPROM interface. If bit 7
of the
General Purpose Pin Control (GPCNTL)
register is
set, this pin drives low when the SYM53C1010 is the bus
master.
A_GPIO2
AA16
I/O
8 mA
SCSI Function A General Purpose I/O pin 2.
This pin
powers up as an input.
A_GPIO3
AC17
I/O
8 mA
SCSI Function A General Purpose I/O pin 3.
This pin
powers up as an input.
A_GPIO4
AB17
I/O
8 mA
SCSI Function A General Purpose I/O pin 4.
This pin
powers up as an output. It can be used as the enable line
for V
PP
, the 12 V power supply to the external flash memory
interface.