PEB24901HV1.2 Lantiq, PEB24901HV1.2 Datasheet - Page 21

• Manufacturer Part Number: PEB24901HV1.2
• Manufacturer: Lantiq

Specifications of PEB24901HV1.2

• Lead Free Status / Rohs Status: Supplier Unconfirmed

PEB 24901
3.2.1.2
Monitor Channel
The monitor channel represents a second method of initiating and reading Quad IEC
DFE-T specific information. Features of the monitor channel are supplementary to the
command/indicate channel. Unlike the command/indicate channel with an emphasis on
status control, the monitor channel provides access to internal bits (maintenance,
overhead) and test functions as local loop-backs and block error counter.
The following chapters describe the principle of monitor handshake in IOM-2, internal
safe guards against blocking of the monitor channel, and features.
3.2.1.2.1 Handshake Procedure
IOM-2 provides a sophisticated handshake procedure for the transfer of monitor
messages. For handshake control two bits are assigned to each IOM-frame (on DIN and
DOUT).
The monitor transmit bit (MX) indicates when a new byte has been issued in the monitor
channel (active low). The transmitter postpones transmitting the next information until
the correct reception has been confirmed. A correct reception will be confirmed by
setting the monitor read bit (MR) to low.
In order to send a monitor message from the control unit to the Quad IEC DFE-T, the
MX-bit on DIN and the MR-bit on DOUT are used. In the opposite direction the Quad IEC
DFE-T handles the MX-bit of the DOUT-pin and watches the MR-bit of the DIN-signal.
Figure 7 demonstrates monitor channel handling with the PEB 2055 (EPIC-1). A two-
byte message is sent from the control unit to the Quad IEC DFE-T which acknowledges
the receipt by returning a two-byte long message in the monitor channel.
The EPIC-1/2 supports different types of monitor transfer. For communication with the
Quad IEC DFE-T, three are of special interest.
Transmit Only. This mode is required when the EPIC sends monitor messages but no
confirmation is returned by the Quad IEC DFE-T.
Transmit and Receive. The EPIC transmits first and receives afterwards. Confirmations
sent by the Quad IEC DFE-T can be read.
Searching for Active Monitor Channels. Listens to the IOM-monitor channel and
reads information issued by the Quad IEC DFE-T autonomously. Nothing is transmitted
by the EPIC.
The EPIC uses a FIFO for transmission and reception. The user therefore does not have
to provide routines for the handshake protocol.
Semiconductor Group
20
02.95