XRT79L71IB datasheet(67/434 Pages) EXAR

67 / 434 page

XRT79L71

REV. 1.0.0

1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - REGISTER/MAP DESCRIPTION

Transmit Level 2 Mode

R/W

Transmit POS-PHY Level 2, Packet Mode:

This READ/WRITE bit-field along with Bits 1 and 0

(Transmit_Mode[1:0]) within the Transmit POS-PHY Interface -

Transmit Control Register - Byte 1 permits the user to configure

the Transmit POS-PHY Interface block to operate in any of the

following modes.· The Level 2, Packet Mode· The Level 2,

Chunk Mode· The Level 3, Packet Mode· The Level 3, Out-of-

Band, Chunk Mode· The Level 3, In-Band, Chunk ModeThe fol-

lowing table presents the relationship between these three bits,

and the corresponding operating mode of the Transmit POS-

PHY Interface block.

A brief description of the Transmit POS-PHY Level 2 and 3

Modes are presented below.

If the Transmit POS-PHY Interface block is configured to

operate in the POS-PHY Level 2 Mode

If the Transmit POS-PHY Interface block is configured to operate

in the POS-PHY Level 2 Mode, then all of the following is true.

• When polling, the Receive POS-PHY Interface block will drive

the TxPPA output pin to the appropriate level (reflecting the

TxFIFO fill-status) within ONE TxPClk period (in lieu of two

TxPClk periods) after sampling a given POS-PHY Port

Address via the TxPAddr[4:0] input pins.

If the Transmit POS-PHY Interface block is configured to operate

in the POS-PHY Level 3 Mode

If the Transmit POS-PHY Interface block is configured to operate

in the POS-PHY Level 3 Mode, then all of the following are true.

• When polling, the Transmit POS-PHY Interface block will drive

the TxPPA output pin to the appropriate level (reflecting the

TxFIFO fill-status) within TWO TxPClk periods (in lieu of one

TxPClk periods) after sampling a given POS-PHY Port

Address via the TxPAddr[4:0] input pins.

Transmit POS-PHY Interface - Transmit Control Register Byte - 1 (Address = 0x0581)

BIT 7

BIT 6

BIT 5

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

Unused

Chunk_Size[2:0]/

TxFIFO_Packet_Fill_Level[2:0]

Transmit POS-PHY Data

Bus Width[1:0]

Transmit Mode[1:0]

R/O

R/W

BIT NUMBER

NAME

TYPE

DESCRIPTION

Resulting Mode of Operation

Level 2, Chunk Mode

Level 3, Out-of-Band Chunk Mode

Level 3, In-Band Chunk Mode

Level 3, Packet Mode

Level 2, Packet Mode

Transmit

Level 2 Mode

Transmit

Mode[1:0]

XRT79L71IB Datasheet(PDF) 67 Page - Exar Corporation

XRT79L71IB Datasheet(HTML) 67 Page - Exar Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL