UPD72862 datasheet(13/36 Pages) NEC

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Data Sheet S14265EJ2V0DS00

µµµµPD72862

2.1.4 Offset_06

Status Register

This register tracks the status information of PCI-bus related events which are relevant to the

µPD72862. “Read”

and “Write” are handled somewhat differently.

Bits

R/W

Description

3-0

Reserved Constant value of 0000.

New capabilities

Constant value of 1. It indicates the existence of the Capabilities List.

6,5

Reserved Constant value of 00.

Fast back-to-back capable Constant value of 1. It indicates that the

µPD72862, as a target,

cannot accept fast back-to-back transactions when the transactions are not to the same agent.

8R/W

Signaled parity error Default value of 0. It indicates the occurrence of any “Data Parity”.

0: No parity detected (default)

1: Parity detected

10,9

DEVSEL timing Constant value of 01. These bits define the decode timing for DEVSEL.

0: Fast (1 cycles)

1: Medium (2 cycles)

2: Slow (3 cycles)

3: undefined

R/W

Signaled target abort Default value of 0. This bit is set by a target device whenever it

terminates a transaction with “Target Abort”.

0: The

µPD72862 did not terminate a transaction with Target Abort

1: The

µPD72862 has terminated a transaction with Target Abort

R/W

Received target abort Default value of 0. This bit is set by a master device whenever its

transaction is terminated with a “Target Abort”.

0: The

µPD72862 has not received a Target Abort

1: The

µPD72862 has received a Target Abort from a bus-master

R/W

Received master abort

Default value of 0. This bit is set by a master device whenever its

transaction is terminated with “Master Abort”. The

µPD72862 asserts “Master Abort” when a

transaction response exceeds the time allocated in the latency timer field.

0: Transaction was not terminated with a Master Abort

1: Transaction has been terminated with a Master Abort

R/W

Signaled system error Default value of 0. It indicates that the assertion of SERR by the

µPD72862.

0: System error was not signaled

1: System error was signaled

R/W

Received parity error Default value of 0. It indicates the occurrence of any PERR.

0: No parity error was detected

1: Parity error was detected

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