BT8375 CONEXANT [Conexant Systems, Inc], BT8375 Datasheet - Page 84

• Manufacturer Part Number: BT8375
• Description: single chip transceivers for T1/E1 and Integrated Service Digital Network (ISDN) primary rate interfaces
• Manufacturer: CONEXANT [Conexant Systems, Inc]

2.0 Circuit Description
2.8 Transmitter
2-56
versatile. It can be used as a single-byte transmit buffer or in any number of bytes,
up to a maximum of 64. As a single-byte FIFO, the Transmit FIFO Empty Status
(TMPTY1) in TDL #1 Status [TDL1_STAT; addr 0AE] and Transmit FIFO
Empty Interrupt (TEMPTY) in Data Link 1 Interrupt Status (ISR2; addr 009] can
be used for byte-by-byte transmissions.
very little microprocessor-interrupt overhead. Block transfers to the FIFO can be
controlled by the Near Empty Threshold in the FIFO Empty Control register
[TDL1_FEC; addr 0AB]. The Near Empty Threshold is a user-programmable
value between 0 and 63 that represents the minimum number of bytes that can
remain in the transmit FIFO before near empty is declared. Once the threshold is
set, the Near Empty Status (TNEAR1) in TDL #1 Status [TDL1_STAT;
addr 0AE] is asserted whenever the Near Empty Threshold is reached. An
interrupt, TNEAR in the Data Link 1 Interrupt Status register [ISR2; addr 009], is
also available to mark this event.
processor must indicate the end of message by writing any value to the TDL #1
End of Message (EOM) Control [TDL1_EOM; addr 0AC]. In FCS mode, the
EOM indicates that the FCS is to be calculated and transmitted following the last
byte in the FIFO; in the Circular Buffer mode, the EOM indicates the end of the
transmit circular buffer.
The Transmit Data Link FIFO #1 [TDL1; addr 0AD] is 64 bytes, and very
Using the Transmit Data FIFO, an entire block of data can be transmitted with
Once an entire message is written into the transmit FIFO or circular buffer, the
Conexant
Fully Integrated T1/E1 Framer and Line Interface
Bt8370/8375/8376
N8370DSE