CS89712
Section 3.2.7, “Status/Control Register Summary”
provides a detailed description of each register.
3.2.6.1 Act-Once Bits
There are four bits that cause a certain action only
once when set. These "Act-Once" bits are: Skip_1
(RxCFG register bit 6), RESET (SelfCTL register
bit 6), ResetRxDMA (BusCTL register bit 6), and
SWint-X (BufCFG register bit 6). To cause the ac-
tion again, the software must set the bit again. Act-
Once bits are always read as clear.
3.2.6.2 Temporal Bits
Temporal bits are bits that are set and cleared by the
Ethernet port automatically. This includes all status
bits in the three status registers (LineST, SelfST,
and BusST), the RxDest bit (BufEvent bit F), and
the Rx128 bit (BufEvent bit B). Like all Event bits,
RxDest and Rx128 are cleared when read by the
software.
3.2.6.3 Interrupt Enable Bits and Events
Interrupt Enable bits end with the suffix iE and are
located in three Configuration registers: RxCFG,
TxCFG, and BufCFG. Each Interrupt Enable bit
corresponds to a specific event. If an Interrupt En-
able bit is set and its corresponding event occurs,
the Ethernet port generates an interrupt.
The bits that report when various events occur are
located in three Event registers and two counters.
The Event registers are RxEvent, TxEvent, and
BufEvent. The counters are RxMISS and TxCOL.
Each Interrupt Enable bit and its associated Event
are identified in Table 35.
An Event bit will be set whenever the specified
event happens, whether or not the associated Inter-
rupt Enable bit is set. All Event registers are cleared
upon read-out by the software.
3.2.6.4 Accept Bits
There are nine Accept bits located in the RxCTL
register, each of which is followed by the suffix A.
Interrupt Enable Bit
(register name)
Event Bit or Counter
(register name)
ExtradataiE (RxCFG)
RuntiE (RxCFG)
CRCerroriE (RxCFG)
RxOKiE (RxCFG)
Extradata (RxEvent)
Runt (RxEvent)
CRCerror (RxEvent)
RxOK (RxEvent)
16colliE (TxCFG)
16coll (TxEvent)
AnycolliE (TxCFG)
“Number-of Tx-colli-
sions” counter is incre-
mented (TxEvent)
JabberiE (TxCFG)
Jabber (TxEvent)
Out-of-windowiE (TxCFG) Out-of-window (TxEvent)
TxOKiE (TxCFG)
TxOK (TXEvent)
MissOvfloiE (BufCFG)
TxColOvfloiE (BufCFG)
RxDestiE (BufCFG)
Rx128iE (BufCFG)
RxMissiE (BufCFG)
TxUnderruniE (BufCFG)
Rdy4TxiE (BufCFG)
RxMISS counter over-
flows past 1FFh
TxCOL counter overflows
past 1FFh
RxDest (BufEvent)
Rx128 (BufEvent)
RxMISS (BufEvent)
TxUnderrun (BufEvent)
Rdy4Tx (BufEvent)
Table 35. Interrupt Enable Bits and Events
Accept bits indicate which types of frames will be
accepted by the CS89712. Four of these bits have
corresponding Interrupt Enable (iE) bits. An Ac-
cept bit and an Interrupt Enable bit are independent
operations. It is possible to set either, neither, or
both bits. The four corresponding pairs of bits are:
IE Bit in RxCFG
ExtradataiE
RuntiE
CRCerroriE
RxOKiE
A Bit in RxCTL
ExtradataA
RuntA
CRCerrorA
RxOKA
If one of the above Interrupt Enable bits is set and
the corresponding Accept bit is clear, the CS89712
DS502PP2
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