CRD8900A-1 Cirrus Logic Inc, CRD8900A-1 Datasheet - Page 55

• Manufacturer Part Number: CRD8900A-1
• Description: KIT EVAL FOR CS8900A
• Manufacturer: Cirrus Logic Inc
• Series: CrystalLAN™r

Specifications of CRD8900A-1

• Main Purpose: Interface, Ethernet
• Utilized Ic / Part: CS8900A
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Other names: 598-1163

DS271F5
4.4.7 Register 4: Receiver Event
(RxEvent, Read-only, Address: PacketPage base + 0124h)
Alternate meaning if bits 8 and 9 are both set (see Section 5.2.10 on page 87 for exception regarding Broadcast
frames).
RxEvent reports the status of the current received frame.
000100
IAHash
Dribblebits
RxOK
Hashed
IndividualAdr
Broadcast
CRCerror
Runt
Extradata
Reset value is: 0000 0000 0000 0100
Notes: 3. All RxEvent bits are cleared upon readout. The host is responsible for processing all event bits.
CS8900A
Crystal LAN™ Ethernet Controller
Dribblebits
Dribblebits
7
F
7
F
4. RxStatus register (PacketPage base + 0400h) is the same as the RxEvent register except RxStatus is
not cleared when RxEvent is read. See Section 5.2 on page 78. The value in the RxEvent register is
undefined when RxDMAOnly bit (Bit 9, Register 3, RxCFG) is set.
Extradata
IAHash
IAHash
Hash Table Index (see Section 5.2.10 on page 87)
will be 000100, where the LSB corresponds to Bit 0.
and only if IAHashA (Register 5, RxCTL, Bit 6) is set, and Hashed (Bit 9) is set. See
Section 5.2.10 on page 87.
ment Error" occurs when Dribblebits and CRCerror (Bit C) are both set.
error, or Extradata error). When RxOK is set, then the length of the received frame is contained
at PacketPage base + 0402h. If RxOKiE (Register 3, RxCFG, Bit 8) is set, there is an interrupt.
Hashed and RxOK (Bit 8) are set, Bits F through A of RxEvent become the Hash Table Index
for this frame [See Section 5.2.10 on page 87 for an exception regarding broadcast frames!].If
Hashed and RxOK are not both set, then Bits F through A are individual event bits as defined
below.
at PacketPage base + 0158h, then this bit is set if, and only if, RxOK (Bit 8) is set and Individ-
ualA (Register 5, RxCTL, Bit A) is set.
dress, then this bit is set if, and only if, RxOK is set and BroadcastA (Register 5, RxCTL, Bit B)
is set.
is an interrupt
there is an interrupt.
ExtradataiE (Register 3, RxCFG, Bit E) is set, there is an interrupt.
These bits identify this as the Receiver Event Register. When reading this register, these bits
If the received frame's Destination Address is accepted by the hash filter, then this bit is set if,
If set, the received frame had from one to seven bits after the last received full byte. An "Align-
If set, the received frame had a good CRC and valid length (i.e., there is not a CRC error, Runt
If set, the received frame had a Destination Address that was accepted by the hash filter. If
If the received frame had a Destination Address which matched the Individual Address found
If the received frame had a Broadcast Address (FFFF FFFF FFFFh) as the Destination Ad-
If set, the received frame had a bad CRC. If CRCerroriE (Register 3, RxCFG, Bit C) is set, there
If set, the received frame was shorter than 64 bytes. If RuntiE (Register 3, RxCFG, Bit D) is set,
If set, the received frame was longer than 1518 bytes. All bytes beyond 1518 are discarded. If
E
E
6
6
Runt
D
D
5
5
CIRRUS LOGIC PRODUCT DATASHEET
CRCerror
C
C
4
4
Broadcast
B
B
3
3
000100
000100
Individual Adr
A
A
2
2
Hashed = 1
Hashed
1
9
1
9
RxOK = 1
RxOK
0
8
0
8
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