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DS3131
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5.3.2 Status and Interrupt Register Description
Register Name:
SM
Register Description:
Status Master Register
Register Address:
0020h
Bit #
7
6
5
4
3
2
1
0
Name
reserved
PPERR
PSERR
SBERT
reserved
Default
0
Bit #
15
14
13
12
11
10
9
8
Name
LBINT
LBE
reserved
Default
0
Note:
Bits that are underlined are read-only; all other bits are read-write.
Bit 2/Status Bit for Change of State in BERT (SBERT). This status bit is set to 1 if there is a major change of
state in the BERT receiver. A major change of state is defined as either a change in the receive synchronization
(i.e., the BERT has gone into or out of receive synchronization), a bit error has been detected, or an overflow has
occurred in either the bit counter or the error counter. The host must read the status bits of the BERT in the BERT
status register (BERTEC0) to determine the change of state. The SBERT bit is cleared when the BERT status
register is read and is not set again until the BERT has experienced another change of state. If enabled through the
SBERT bit in the interrupt mask for SM (ISM), the setting of this bit causes a hardware interrupt at the PCI bus
through the PINTA signal pin and also at the LINT if the local bus is in configuration mode.
Bit 3/Status Bit for PCI System Error (PSERR). This status bit is a software version of the PCI bus hardware
pin PSERR. It is set to 1 if the PCI bus detects an address parity error or other PCI bus error. The PSERR bit is
cleared when read and is not set again until another PCI bus error has occurred. If enabled through the PSERR bit
in the interrupt mask for SM (ISM), the setting of this bit causes a hardware interrupt at the PCI bus through the
PINTA signal pin and also at the LINT if the local bus is in configuration mode. This status bit is also reported in
the control/status register in the PCI configuration registers (Section 10).
Bit 4/Status Bit for PCI System Error (PPERR). This status bit is a software version of the PCI bus hardware
pin PPERR. It is set to 1 if the PCI bus detects parity errors on the PAD and PCBE buses as experienced or
reported by a target. The PPERR bit is cleared when read and is not set again until another parity error has been
detected. If enabled through the PPERR bit in the interrupt mask for SM (ISM), the setting of this bit causes a
hardware interrupt at the PCI bus through the PINTA signal pin and also at the LINT if the local bus is in
configuration mode. This status bit is also reported in the control/status register in the PCI configuration registers
(Section 10).
Bit 14/Status Bit for Local Bus Error (LBE). This status bit applies to the local bus when it is operated in PCI
bridge mode. It is set to 1 when the local bus LRDY signal is not detected within nine LCLK periods. This
indicates to the host that an aborted local bus access has occurred. If enabled through the LBE bit in the interrupt
mask for SM (ISM), the setting of this bit causes a hardware interrupt at the PCI bus through the PINTA signal pin
and also at the LINT if the local bus is in configuration mode. The LBE bit is meaningless when the local bus is
operated in the configuration mode and should be ignored.
Bit 15/Status Bit for Local Bus Interrupt (LBINT). This status bit is set to 1 if the local bus LINT signal has
been detected as asserted. This status bit is only valid when the local bus is operated in PCI bridge mode. The
LBINT bit is cleared when read and is not set again until the LINT signal pin once again has been detected as
asserted. If enabled through the LBINT bit in the interrupt mask for SM (ISM), the setting of this bit causes a
hardware interrupt at the PCI bus through the PINTA signal pin. The LBINT bit is meaningless when the local bus
is operated in the configuration mode and should be ignored.