MPC8280 datasheet(1110/1386 Pages) FREESCALE

1110 / 1386 page

ATM AAL2

MPC8280 PowerQUICC II Family Reference Manual, Rev. 1

33-4

Freescale Semiconductor

— A separate queue for every VP | VC | CID or a common queue for multiple VP | VC | CID

combinations

— Receive one or multiple VP | VC | CIDs directly to a specific TX queue to enable switching

— Sequence number (SN) protection check for CPS-PDU

— CRC5 (HEC) check to detect errors in the CPS-PH of the CPS-Packet

— OSF (offset field) of the STF (start of frame) check (a valid value is less than 48)

— An SDU length limit parameter (Max_SDU_Deliver_Length) per ATM VC

— Odd parity check for the STF octet of the CPS-PDU

•

CPS Transmitter

— Reassemble CPS PDU directly from external memory

— Perform CPS-PDU padding as needed

— Insert Sequence Number bit of the CPS-PDU

— Parity bit is calculated to provide odd parity over the STF octet

— Calculation of CRC-5 on the first 19 bits of the CPS-PH

— UUI field in the CPS-Packet header is programmed according to the value of the CPS_UUI

parameter (per packet)

— A free running counter (per TX Queue) is decremented for each packet sent.

•

SSSAR Receiver

— Reassemble CPS packets from the same CID into an SSSAR SDU

— A separate queue for every PHY | VP | VC | CID

— Perform all the above mentioned CPS receiver functions

— A Ras_Timer mode is provided. When the Ras_Timer expires the buffer is closed with a timer

expired error. The next packet received starts a new SSSAR SDU in a new buffer.

— The SDU length is checked. If the frame exceeds the length limit

(SSSAR_Max_SDU_Length), the receiver discards the rest of the packets from the current

frame, closes the buffer and reports a Max_SDU violation error in the BD. The next packet

received starts a new SSSAR SDU in a new buffer.

— Partial Packet Discard. If no buffer is available when a packet arrives, the receiver enters a

frame hunt state and discards each incoming packet from the current frame.

— The UUI field is stored for the host into the RxBD after receiving the whole SSSAR frame.

•

SSSAR Transmitter

— Segmentation of SSSAR SDUs from SSSAR TX queue into CPS packets

— An SSSAR TX queue may contain several CIDs

— Performs all the above mentioned CPS transmitter functions

— A programmable segment length (Seg_Len) is copied from the SSSAR SDU into the CPS

packet payload, except for when at the end of the frame or buffer.

— UUI mode available. When UUI mode is enabled, the SSSAR UUI is copied from the byte

following the last byte of the frame.

MPC8280 Datasheet(PDF) 1110 Page - Freescale Semiconductor, Inc

MPC8280 Datasheet(HTML) 1110 Page - Freescale Semiconductor, Inc

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