ML7065-033 User’s Manual
Chapter 7 Commands
20
7.3 MAC Commands
The data that flows on SCI comprises a header and a payload. The figure below shows the format of the entire
data.
Data Format
See below for the header format of the data that is transmitted from a host system to MAC.
SCI header
Payload
LSB
MSB
Field name Request
Length
Primitive Code
Payload
Length
1 byte
1 byte
1 byte
Value subtracted by 1 from the value of
Length field
SCI Header Format (1)
The SCI header of the data that is transmitted from a host system to MAC comprises three fields: Request field,
Length field, and Primitive Code field. See below for the specification of each field.
Request field:
Only bit 0 and bit “1” are used. Bit 2 to bit 7 are not used (always set to “0”).
•
bit
0:
This bit is set to “1” when the host system is ready to receive data from MAC. This bit is set to “0”
when the host system cannot receive data from MAC.
•
bit
1:
This bit is set to “1” when the host system transmits data to MAC.
•
bit 2 to bit 7:
Unused.
Length field:
The length following the Length field (Primitive Code + Payload) is set. The unit is bytes.
Primitive Code field:
The Primitive Code of the data (request) that is transmitted from the host system is set. See the table in
Section 7.1, “List of Commands” for the value to be set.
* If a value even smaller or greater than the (Primitive Code + Payload) value is set for the Length field, MAC then
becomes unable to perform Primitive analysis, so that MAC will operate abnormally. Therefore, be sure to set the
exact (Primitive Code + Payload) value for the Length field.
Payload
SCI header
