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RCV56HCF PCI/CardBus Modem Designer’s Guide
1129
ROCKWELL PROPRIETARY INFORMATION
3-7
Table 3-2. Bus Interface Pin Signal Definitions
Label I/O Type Signal Name/Description
SYSTEM
XIN,
XOUT
It
Ot2
Crystal In and Crystal Out.
Connect XIN and XOUT to a 28.224 MHz external crystal circuit.
VDD PWR
Digital Supply Voltage.
Connect to 3.3V.
GND GND
Digital Ground.
Connect to digital ground.
CARDBUS# It
CardBus Interface Select.
Selects CardBus (low) or PCI Bus (high) drive strength. For PCI Bus, connect to
VCC through 1K ohm.
VGG1 PWR
I/O Voltage Tolerance Reference.
Connect to VCC.
VIO PWR
I/O Signaling Voltage Source.
Connect to 3.3V.
PCI BUS INTERFACE
PCICLK Ip
(in)
PCI Bus Clock.
The PCICLK (PCI Bus CLK signal) input provides timing for all transactions on PCI.
CLKRUN# Ip,
(in, o/d,
s/t/s)
Clock Running.
CLKRUN# is an input used to determine the status of CLK and an open drain output used
to request starting or speeding up CLK. Connect to GND through 1K
Ω
for PCI designs.
PCIRST# Ip
(in)
PCI Bus Reset.
PCIRST# (PCI Bus RST# signal) is used to bring PCI-specific registers, sequencers, and
signals to a consistent state.
AD[31:0] I/Opts
(t/s)
Multiplexed Address and Data.
Address and Data are multiplexed on the same PCI pins.
CBE[3:0]# I/Opts
(t/s)
Bus Command and Bus Enable.
Bus Command and Byte Enables are multiplexed on the same PCI pins.
During the address phase of a transaction, C/BE[3:0]# define the bus command. During the data phase,
C/BE[3:0]# are used as Byte Enables.
PAR I/Opts
(t/s)
Parity.
Parity is even parity across AD[31::00] and C/BE[3::0]#. The master drives PAR for address and
write data phases; the Bus Interface drives PAR for read data phases.
FRAME# I/Opsts
(s/t/s)
Cycle Frame.
FRAME# is driven by the current master to indicate the beginning and duration of an access.
IRDY# I/Opsts
(s/t/s)
Initiator Ready.
IRDY# is used to indicate the initiating agent’s (bus master’s) ability to complete the current
data phase of the transaction. IRDY# is used in conjunction with TRDY#.
TRDY# I/Opsts
(s/t/s)
Target Ready.
TRDY# is used to indicate s the Bus Interface’s ability to complete the current data phase of
the transaction. TRDY# is used in conjunction with IRDY#.
STOP# I/Opsts
(s/t/s)
Stop.
STOP# is asserted to indicate the Bus Interface is requesting the master to stop the current
transaction.
IDSEL Ip
(in)
Initialization Device.
IDSEL input is used as a chip select during configuration read and write transactions.
DEVSEL# I/Opsts
(s/t/s)
Device Select.
When actively driven, DEVSEL# indicates the driving device has decoded its address as the
target of the current access. As an input, DEVSEL# indicates whether any device on the bus has been
selected.
TRDY# I/Opts
(t/s)
Reques
t. TRDY# is used to indicate to the arbiter that this agent desires use of the bus.
GNT# I/Opts
(t/s)
Grant.
GNT# is used to indicate to the agent that access to the bus has been granted.