Le58083
Data Sheet
Upstream C/I Channel
The SC channel, which includes the six C/I channel bits, is transmitted upstream every frame. The bit definitions for the upstream
C/I channel are shown below. These bits are transmitted by the Le58083 Octal SLAC device (Most significant bit first).
GCI Format
<------------------------ Upstream SC Octet ------------------>
MSB
7
LSB
0
6
5
4
3
2
1
C3
CDB
CDA
C3
CDB
CDA
2
MR
MX
1
1
1
2
2
|<----------------------- C/I FIELD ------------->|
Upstream Bit Definitions of the C/I field require the programmable I/O ports to be programmed as inputs. Otherwise, these bits
follow the downstream C/I bits for CD1C, CD2C, and C3C.
CDAC: Debounced CD1C bit of channel X.
CDBC: The filtered CD2C bit of channel x in non-E1 demultiplexed mode or the filtered CD1BC bit in the E1 demultiplexed mode.
C3C–C3C of channel C.
In GCI mode, C4 and C5 are not available as upstream C/I data but can be obtained by reading the SLIC device I/O register.
Monitor Channel
The Monitor Channel (see Figure 28) is used to read and write the Le58083 Octal SLAC device’s coefficient registers, to read
the status of the device and the contents of the internal registers, and to provide supplementary signaling. Information is
transferred on the Monitor Channel using the MR and MX bits of the SC channel, providing a secure method of data exchange
between the upstream and downstream devices.
The Monitor byte is the third byte in the 4 byte GCI channel and is received every 125 µs over the DU or DD pins. A Monitor
command consists of one address byte, one or more command bytes, and is followed by additional bytes of input data as
required. The command may be followed by the Le58083 Octal SLAC device sending data bytes upstream via the DU pin.
Monitor Channel Protocol
Figure 28. Maximum Speed Monitor Handshake Timing
2nd Byte
1st Byte
3rd Byte
MX
MX
Transmitter
Receiver
EOM
MR
MR
ACK
1st Byte
ACK
2nd Byte
ACK
3rd Byte
125 µs
■ An inactive (high) MX and MR pair bit for two or more consecutive frames shows an idle state on the monitor channel
and the end of message (EOM).
67
Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
