SAB 82525
SAB 82526
SAF 82525
SAF 82526
Receive Address Byte Low Register 1 (READ/WRITE)
7
0
RAL1
RAL1
(28/68)
The general function (READ/WRITE) and the meaning or contents of this register depends on
the selected operating mode:
– Auto-/non-auto mode (16-bit address) – WRITE only:
RAL1 can be programmed with the value of the first individual low address byte.
–
Auto-/non-auto mode (8-bit address) – WRITE only:
According to X.25 LAPB protocol, the address in RAL1 is recognized as COMMAND
address.
–
Transparent mode 1 (high byte address recognition) – READ only:
RAL1 contains the byte following the high byte of the address in the receive frame (i.e.
the second byte after the opening flag).
–
–
Transparent mode 0 (no address recognition) – READ only:
RAL1 contains the first byte after the opening flag (first byte of received frame).
Extended transparent modes 0, 1 – READ only:
RAL1 contains the actual data byte currently assembled at the R × D pin, by passing the
HDLC receiver (fully transparent reception without HDLC framing).
Receive Address Byte Low Register 2 (WRITE)
7
0
RAL2
RAL2
(29/69)
Value of the second individual programmable low address byte. If a one byte address field is
selected, RAL2 is recognized as RESPONSE according to X.25 LAPB protocol.
Semiconductor Group
97