CS8900A
Crystal LAN™ ISA Ethernet Controller
4.4.21 Register 18: Bus Status
(BusST, Read-only, Address: PacketPage base + 0138h)
7
6
5
4
3
2
1
9
0
TxBidErr
011000
F
E
D
C
B
A
8
Rdy4Tx NOW
BusST describes the status of the current transmit operation.
011000
These bits provide an internal address used by the CS8900A to identify this as the Bus Status
Register. When reading this register, these bits will be 011000, where the LSB corresponds to
Bit 0.
TxBidErr
If set, the host has commanded the CS8900A to transmit a frame that the CS8900A will not
send. Frames that the CS8900A will not send are:
1) Any frame greater than 1514 bytes, provided that InhibitCRC
(Register 9, TxCMD, Bit C) is clear.
2) Any frame greater than 1518 bytes.
Note that this bit is not set when transmit frames are too short.
Rdy4TxNOW
Rdy4TxNOW signals the host that the CS8900A is ready to accept a frame from the host for
transmission. This bit is similar to Rdy4Tx (Register C, BufEvent, Bit 8) except that there is no
interrupt associated with Rdy4TxNOW. The host can poll the CS8900A and check
Rdy4TxNOW to determine if the CS8900A is ready for transmit. (See Section 5.7 on page 99
for a description of the transmit bid process.)
Reset value is: 0000 0000 0001 1000
CIRRUS LOGIC PRODUCT DATA SHEET
68
DS271PP3
CIRRUS [ CIRRUS LOGIC ]
