AMIS−49587
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Table 47. DESCRIPTION OF THE MAC_Frame FIELD
Field Name Length Value Description
Initial Credit 3 bits b7−b5 0h to 7h Initial Credit
Current Credit 3 bits b4−b2 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 b23−b12
Not used Slave Mode (Filled by MAC layer)
000h to FFFh Master Mode
Destination Address 12 bits b11−b0 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 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 Value Description
OK FFh No error has been found
LM_TU1 00h MA Data Confirm NEG
Resources Temporary Unavailable at the MAC sub−layer
LM_SE 03h Syntax Error at the MAC sub−layer
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 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
