DS33R11 Ethernet Mapper with Integrated T1/E1/J1 Transceiver

11.5.3 Receive Serial Interface

Serial Receive Registers are used to control the HDLC Receiver associated with each Serial Interface. Note that throughout this document HDLC Processor is also referred to as “Packet Processor”. The receive packet processor block has seventeen registers.

11.5.3.1 Receive Serial Register Bit Descriptions

 

 

 

 

 

Register Name:

 

 

LI.RSLCR

 

 

 

 

 

Register Description:

 

Receive Serial Interface Configuration Register

 

 

Register Address:

 

100h

 

 

 

 

 

Bit #

7

6

5

 

4

3

2

1

0

Name

 

 

 

 

 

 

 

 

 

 

 

 

-

-

 

-

 

-

-

-

-

RDENPLT

Default

 

0

0

 

0

 

0

0

0

0

0

Bit 0: Receive Data Enable Polarity (RDENPLT) Receive Data Enable Polarity. If set to 1, RDEN Low enables reception of the bit.

Register Name:

 

 

LI.RPPCL

 

 

 

 

 

Register Description:

 

Receive Packet Processor Control Low Register

 

 

Register Address:

 

101h

 

 

 

 

 

Bit #

7

6

5

4

3

2

1

0

Name

 

-

-

 

RFPD

RF16

RFED

RDD

RBRE

RCCE

Default

 

0

0

 

0

0

0

0

0

0

Bit 5: Receive FCS Processing Disable (RFPD) – When equal to 0, FCS processing is performed and FCS is appended to packets. When set to 1, FCS processing is disabled (the packets do not have an FCS appended). In X.86 mode, FCS processing is always enabled.

Bit 4: Receive FCS-16 Enable (RF16) – When 0, the error checking circuit uses a 32-bit FCS. When 1, the error checking circuit uses a 16-bit FCS. This bit is ignored when FCS processing is disabled. In X.86 mode, the FCS is always 32 bits.

Bit 3: Receive FCS Extraction Disable (RFED) – When 0, the FCS bytes are discarded. When 1, the FCS bytes are passed on. This bit is ignored when FCS processing is disabled. In X.86 mode, FCS bytes are discarded.

Bit 2: Receive Descrambling Disable (RDD) – When equal to 0, X43+1 descrambling is performed. When set to 1, descrambling is disabled.

Bit 1: Receive Bit Reordering Enable (RBRE) – When equal to 0, reordering is disabled and the first bit received is expected to be the MSB DT [7] of the byte. When set to 1, bit reordering is enabled and the first bit received is expected to be the LSB DT [0] of the byte.

Bit 0: Receive Clear Channel Enable (RCCE) – When equal to 0, packet processing is enabled. When set to 1, the device is in clear channel mode and all packet-processing functions except descrambling and bit reordering are disabled.

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Maxim DS33R11 specifications Receive Serial Interface, Li.Rslcr, Li.Rppcl