S Registers 51

S74 V.80 Synchronous Access Mode Sub-parameters. Nonstorable.

Bits 1-0. Character transmitted on idle in transmit mode

■00 Transmit 8 bits SYN. the receiver does not hunt for synchronization sequence.

■01 Transmit 8 bits SYN. the receiver hunt for 8 bits SYN sequence.

■10 Transmit 16 bits SYN. the receiver hunt for 16 bits SYN sequence.

Bit 2. Character transmitted on idle in framed mode

■0 Transmit HDLC flags

■1 Transmit marks

Bit 3. Character transmitted on underrun in framed mode

■

0 Transmit abort

■

1 Transmit flag

Bit 4. Half duplex option (not used)

Bits 6-5. CRC type

■ 00 CRC generation and checking disabled

■ 01 Use 16 bits CRC

■ 10 Use 32 bits CRC

■

11 not used

Bit 7. NRZI encoding

 

S75 V.80 Synchronization Sequence (first byte). Synchronization sequence used while

in synchronous access mode.When using 16 bits SYN, this register represent the

first 8 bits. Nonstorable. Default is 256

 

S76 V.80 Synchronization Sequence (second byte). Last 8 bits of a 16 bits SYN

sequence. Nonstorable. Default is 256.

 

S77 Report period of the nb of octets in rx buffer. Nonstorable. Default is 256.

 

S78 Bits 7-6. V.42 Dictionary size (V25ter only). Nonstorable. Default is 256.

00 512 characters

■

10 2048 characters

■

01 1024 characters

■ 11 Maximum dictionary size characters

Bits 5-0. Max coded string length (V25ter only) 6 to 64, other value reserved.

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3Com PC Card manual First 8 bits. Nonstorable. Default is