DS3134
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Signal Description:
Signal Type:
This signal provides information on even parity across both the PAD address/data bus and the PCBE bus
command/byte enable bus. When the device is an initiator, this signal is an output for writes and input for
reads and is updated on the rising edge of PCLK. When the device is a target, this signal is input for
writes and an output for reads and is sampled on the rising edge of PCLK. When the device is not
involved in a bus transaction, PPAR is tri-stated.
PCI Bus Parity
Input / Output (tri-state capable)
Signal Name:
Signal Description:
Signal Type:
This active low signal is created by the bus initiator and is used to indicate the beginning and duration of a
bus transaction. PFRAME* is asserted by the initiator during the first clock cycle of a bus transaction and
it will remain asserted until the last data phase of a bus transaction. When the device is an initiator, this
signal is an output and is updated on the rising edge of PCLK. When the device is a target, this signal is
input and is sampled on the rising edge of PCLK. When the device is not involved in a bus transaction,
PFRAME* is tri-stated.
PFRAME*
PCI Cycle Frame
Input / Output (tri-state capable)
Signal Name:
Signal Description:
Signal Type:
This active low signal is created by the initiator to signal the target that it is ready to send/accept or to
continue sending/accepting data. This signal handshakes with the PTRDY* signal during a bus
transaction to control the rate at which data transfers across the bus. During a bus transaction, PIRDY* is
deasserted when the initiator cannot temporarily accept or send data and a wait state is invoked. When the
device is an initiator, this signal is an output and is updated on the rising edge of PCLK. When the device
is a target, this signal is input and is sampled on the rising edge of PCLK. When the device is not
involved in a bus transaction, PIRDY* is tri-stated.
PIRDY*
PCI Initiator Ready
Input / Output (tri-state capable)
Signal Name:
Signal Description:
Signal Type:
This active low signal is created by the target to signal the initiator that it is ready to send/accept or to
continue sending/accepting data. This signal handshakes with the PIRDY* signal during a bus transaction
to control the rate at which data transfers across the bus. During a bus transaction, PTRDY* is deasserted
when the target cannot temporarily accept or send data and a wait state is invoked. When the device is a
target, this signal is an output and is updated on the rising edge of PCLK. When the device is an initiator,
this signal is input and is sampled on the rising edge of PCLK. When the device is not involved in a bus
transaction, PTRDY* is tri-stated.
PTRDY*
PCI Target Ready
Input / Output (tri-state capable)