AMIS49587
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48
Table 47. DESCRIPTION OF THE MAC_Frame FIELD
Field Name
Length
Value
Description
Initial Credit
3 bits b7b5
0h to 7h
Initial Credit
Current Credit
3 bits b4b2
0h to 7h
Current Credit = Initial Credit
Delta Credit
2 bits b1,b0
0h to 3h
Delta Credit is Received Delta Credit for Slave mode and 0 for
Master mode
Source Address
12 bits b23b12
Not used
Slave Mode (Filled by MAC layer)
000h to FFFh
Master Mode
Destination Address
12 bits b11b0
000h to FFFh
Destination MAC address of the target station DLC
Pad length
1 byte
Not used
Filled by MAC layer
M_sdu
up to 242 bytes
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 AMIS49587 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. TRANSMISSION STATUS
Field Name
Value
Description
OK
FFh
No error has been found
LM_TU1
00h
MA Data Confirm NEG
Resources Temporary Unavailable at the MAC sublayer
LM_SE
03h
Syntax Error at the MAC sublayer
LM_TU2
0Ah
Command not authorized or Asic is not synchronized on the mains
LM_TU3
14h
PLC buffer not free or Asic is busy
Resources Temporary Unavailable at the MAC sublayer
LM_TU4
1Eh
PLC buffer not free or Asic is busy
Resources Temporary Unavailable at the MAC sublayer
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 AMIS49587 (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 AMIS49587 local PHY layer to indicate that a subframe has not been received
correctly, due to either a method not found, or a non recognition of the Start Subframe Delimiter (SSD).
Frame Format:
<STX>
Length
0xA0 (SPY_No_SubFrame)
SpyData
CHK