CS8900A-IQR Cirrus Logic Inc, CS8900A-IQR Datasheet - Page 106

• Manufacturer Part Number: CS8900A-IQR
• Description: Ethernet ICs IC 10Mbps Ethernet Controller 5V
• Manufacturer: Cirrus Logic Inc

Specifications of CS8900A-IQR

• Ethernet Connection Type: 10Base- 2, 10Base- 5, 10Base- F, 10Base- T
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Product: Ethernet Controllers
• Standard Supported: IEEE 802.3
• Data Rate: 10 Mbps
• Maximum Operating Temperature: + 85 C
• Package / Case: LQFP-100
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

CS8900A may not auto-select the 10BASE-T
media. The cause of this situation is described
in the following paragraphs.
The original IEEE 802.3 specification requires
the MAC to wait until 4 valid link-pulses are re-
ceived before asserting Link-OK. Any time an
invalid link-pulse is received, the count is re-
started. When auto-negotiation occurs, a
transmitter sends FLPs (auto-negotiation Fast
Link Pulses) bursts instead of the original
IEEE 802.3 NLP (Normal Link Pulses).
Notes: 8. If the TxPadDis bit is clear and InhibitCRC is set and the CS8900A is commanded to send a frame of
106
Dis (Bit D)
TxPad-
Register 9, TxCMD
0
0
1
1
9. The CS8900A will not send a frame with TxLength less than 3 bytes.
InhibitCRC
length less than 60 bytes, the CS8900A pads.
(Bit C)
0
1
0
1
3 < TxLength < 60
Pad to 60 and add
send without CRC
pads and without
pads, and add
Pad to 60 and
Send without
Send without
CRC
CRC
CRC
CIRRUS LOGIC PRODUCT DATASHEET
Table 36. Transmit Frame Length
Host specified transmit length at 0146h (in bytes)
Send frame and add
CRC [Normal Mode]
Send frame and add
Send frame without
Send frame without
60 < TxLength <
1514
CRC
CRC
CRC
If the hub is attempting to auto-negotiate with
the CS8900A, the CS8900A will never get
more than 1 "valid" link pulse (valid NLP). This
is not a problem if the CS8900A is already
sending link-pulses, because when the hub re-
ceives NLPs from the CS8900A, the hub is re-
quired to stop sending FLPs and start sending
NLPs. The NLP transmitted by the hub will put
the CS8900A into Link-OK.
However, if the CS8900A is in Auto-Switch
mode, the CS8900A will never send any link-
pulses, and the hub will never change from
sending FLPs to sending NLPs.
1514 < TxLength < 1518
Send frame without
Send frame without
Will not send
Will not send
Crystal LAN™ Ethernet Controller
CRC
CRC
TxLength > 1518
Will not send
Will not send
Will not send
Will not send
CS8900A
DS271F5