cx28560 Mindspeed Technologies, cx28560 Datasheet - Page 143

• Manufacturer Part Number: cx28560
• Description: Hdlc Controller
• Manufacturer: Mindspeed Technologies

CX28560 Data Sheet
5.9
5.9.1
Table 5-54. CX28560 Receive Header Format
28560-DSH-001-B
31:27
26:16
15:12
Bit
9:0
11
10
RSVD
CHANNEL
MSG STATUS
SOP
EOP
LENGTH
Field Name
POS-PHY Transaction Headers and Packets
Receive POS-PHY Data Bus
Data is accumulated in channel buffers in the CX28560 until either an End Of Message is
detected, or enough data has been collated to form a fragment (as configured by the user).
Once one of these conditions has been met, a fragment header is prepared, and the data is
sent (preceded by the header) to the system over a 32 bit POS-PHY bus. All fragments
sent to the system will be of equal length (as configured) except for the last fragment
which contains only the last bytes of the message and may contain as little as 0 bytes of
actual data.
Value
—
—
0
0
0
1
2
3
4
5
6
7
0
1
0
1
Reserved.
Logical Channel Number.
Message Error Encoding.
No Error Occurs.
Overflow.
An internal buffer overflow occurred while the message was being received.
Change Of Frame Alignment (COFA)
A COFA condition was detected while the message was being received.
Out Of Frame (OOF)
A OOF condition was detected while the message was being received.
Abort Condition
An abort pattern (at least seven consecutive ones) was detected at the end of the message.
Too Long Message
The message received length reached the maximum set by the relevant maximum length
register.
Message Alignment Error
The number of bits received in the message was not a multiple of 8 – i.e., the message was
not byte aligned.
FCS Error
The calculated FCS did not match that which was received with the message.
This fragment is not the first fragment of a packet.
This fragment is the first fragment of a packet.
This fragment is not the last fragment of a packet. The STATUS bits are not valid.
This fragment is the last fragment of a packet. The STATUS bits are valid.
Payload Length.
The number of bytes of data that follow the fragment header. When the EOP bit is not set
this will always be the maximum length of a fragment. When the EOP bit is set, this field
should be consulted to determine the number of data bytes contained in the fragment.
Mindspeed Technologies™
Advance Information
Description
The CX28560 Memory Organization
5
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