3Com PC Card User Manual page 55

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.
S Registers 51