AMIS-49587_P2 Datasheet, PDF (48/55 Pages) ON Semiconductor – Power Line Carrier Modem

AMIS--49587
Table 47. DESCRIPTION OF THE MAC_Frame FIELD
Field Name
Initial Credit
Current Credit
Delta Credit
Length
3 bits b7--b5
3 bits b4--b2
2 bits b1,b0
Value
0h to 7h
0h to 7h
0h to 3h
Source Address
Destination Address
Pad length
M_sdu
12 bits b23--b12
12 bits b11--b0
1 byte
up to 242 bytes
Not used
000h to FFFh
000h to FFFh
Not used
Description
Initial Credit
Current Credit = Initial Credit
Delta Credit is Received Delta Credit for Slave mode and 0 for
Master mode
Slave Mode (Filled by MAC layer)
Master Mode
Destination MAC address of the target station DLC
Filled by MAC layer
MAC service data unit, the application data from the LLC layer
implemented in the external processor.
7.4.3 MA_DATA_Confirm
The MA_DATA_Confirm is sent from AMIS--49587 to a
external controller (SLAVE or MASTER) either as positive
acknowledgment when a MA_DATA_Request has
successfully been transmitted by the physical layer, or as
negative acknowledgment when the transmission has been
refused. The positive acknowledgment is sent after the
frame transmission on the mains and before the beginning
of the repetition (if the credit is higher than zero). The
Transmission_Status byte contains a value corresponding at
this positive or negative acknowledgment. The different
values for the Transmission_Status field are described
Table 48.
Table 48. TRANSMISSION STATUS
Field Name
OK
LM_TU1
Value
FFh
00h
Description
No error has been found
MA Data Confirm NEG
Resources Temporary Unavailable at the MAC sub--layer
LM_SE
LM_TU2
LM_TU3
03h
Syntax Error at the MAC sub--layer
0Ah
Command not authorized or Asic is not synchronized on the mains
14h
PLC buffer not free or Asic is busy
Resources Temporary Unavailable at the MAC sub--layer
LM_TU4
1Eh
PLC buffer not free or Asic is busy
Resources Temporary Unavailable at the MAC sub--layer
Frame Format:
<STX>
Length
0x52 (MA_Data_Confirm)
Transmission_Status
CHK
7.4.4 MA_DATA_Indication_Bad_CRC
The MA_Data_Indication_Bad_CRC is sent from the AMIS--49587 (Client or Server) to the external micro controller to
deliver an erroneous frame. This command is only used if the Bad CRC transmitting option is chosen during the configuration.
The frame with errors can be used by the external controller to analyze the faults.
Frame Format:
<STX>
Length
0x53 (MA_Data_Indication_Bad_CRC)
MAC_Frame
CHK
7.4.5 SPY_No_SubFrame
The SPY_No_SubFrame is sent by the AMIS--49587 local PHY layer to indicate that a sub--frame has not been received
correctly, due to either a method not found, or a non recognition of the Start Sub--frame Delimiter (SSD).
Frame Format:
<STX>
Length
0xA0 (SPY_No_SubFrame)
SpyData
CHK
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