7-15
Register Descriptions
PCI INTPINSEL (Interrupt Pin Select) Register
Type: R
Internal Registers Subgroup: PCI Configuration Header
Byte Address: 3Dh
PCI MINGNT (Minimum Grant) Register
Type: R
Internal Registers Subgroup: PCI Configuration Header
Byte Address: 3Eh
Table 7-24. Interrupt Pin Select Register
Bit(s)
rw
Reset
Value
Description/Function
7:0
r
1h
INTPS[7:0]:
The Interrupt Pin register specifies which PCI
interrupt pin the device (or device function) uses. The AIC-6915,
as a single function PCI device, must use INTA_ and have a
default value of 1h. The default value can be changed to a value
read from an external serial EEPROM if BR_A1 pin is asserted
when PCI_PCIRST_ is deasserted. This feature enables the
integration of multiple AIC-6915 devices on the same PCI card (as
a multiport Ethernet NIC) and treats the card as one PCI device
with multiple functions having different interrupt lines.
Table 7-25. Minimum Grant Register
Bit(s)
rw
Reset
Value
Description/Function
7:0
r
08h
MINGNT[7:0]:
The Minimum Grant register indicates the desired
PCI_GNT_
asserted period needed to complete burst transfer of
the device data buffer, assuming that the intended target does not
extend the transfer time by use of PCI_TRDY_. The value read
from the register specifies a period of time in units of 0.25
microseconds. The AIC-6915’s MINGNT register value is 8h
which is the minimum time to burst out 256-byte buffer.
The default value can be changed to a value read from an external
serial EEPROM if the BR_A1 signal pin is asserted when
PCIRST_
is deasserted.
