Cirrus Logic CS8900A - Manual (Page 57)

DS271F5 57
CS8900A
Crystal LAN™ Ethernet Controller
CIRRUS LOGIC PRODUCT DATASHEET
4.4.9 Register 7: Transmit Configuration
(TxCFG, Read/Write, Address: PacketPage base + 0106h)
Each bit in TxCFG is an interrupt enable. When set, the interrupt is enabled as described below. When clear, there
is no interrupt.
000111 These bits provide an internal address used by the CS8900A to identify this as the Transmit
Configuration Register.
Loss-of-CRSiE If the CS8900A starts transmitting on the AUI and does not see the Carrier Sense signal at the
end of the preamble, an interrupt is generated if this bit is set. Carrier Sense activity is reported
by the CRS bit (Register 14, LineST, Bit E).
SQErroriE When set, an interrupt is generated if there is an SQE error. (At the end of a transmission on
the AUI, the CS8900A expects to see a collision within 64 bit times. If this does not happen,
there is an SQE error.)
TxOKiE When set, an interrupt is generated if a packet is completely transmitted.
Out-of-windowiE When set, an interrupt is generated if a late collision occurs (a late collision is a collision which
occurs after the first 512 bit times). When this occurs, the CS8900A forces a bad CRC and ter-
minates the transmission.
JabberiE When set, an interrupt is generated if a transmission is longer than approximately 26 ms.
AnycolliE When set, if one or more collisions occur during the transmission of a packet, an interrupt oc-
curs at the end of the transmission
16colliE If the CS8900A encounters 16 normal collisions while attempting to transmit a particular packet,
the CS8900A stops attempting to transmit that packet. When this bit is set, there is an interrupt
upon detecting the 16th collision.
After reset, if no EEPROM is found by the CS8900A, then the register has the following initial state. If an EEPROM
is found, then the register's initial value may be set by the EEPROM. See Section 3.3 on page 19.
Reset value is: 0000 0000 0000 0111
Notes: Bit 8 (TxOKiE) and Bit B (AnycolliE) are interrupts for normal transmit operation. Bits 6, 7, 9, A, and F
Notes:are interrupts for abnormal transmit operation.
4.4.10 Register 8: Transmitter Event
(TxEvent, Read-only, Address: PacketPage base + 0128h)
TxEvent gives the event status of the last packet transmitted.
7 6 5 4 3 2 1 0
SQE erroriE Loss-of-CRSiE 000111
F E D C B A 9 8
16colliE AnycolliE JabberiE Out-of-window TxOKiE
7 6 5 4 3 2 1 0
SQEerror Loss-of-CRS 001000
F E D C B A 9 8
16coll Number-of-Tx-collisions Jabber Out-of-window TxOK