Communication Status; Table 13.5.2A Meaning Of Status Code St3-0 For Master, Slave Transmit; Table 13.5.2B Meaning Of Status Code St3-0 For Master Receive - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

13.5.2 Communication status

In the status register, there are four bits ST3-0 indicating the status code. After the status code has been
set, interrupt request is generated. During the interrupt routine, the communication status can be
investigated by reading the status register. But at the beginning of master, slave and multiaddress receive,
no interrupt will be generated
(1) Master, slave data transmit (transmit interrupt occurs)
When the unit won the arbitration in multiaddress or master address field, it becomes master unit. Then
data/command is transmitted to or data is received from the slave, and the status code ST3-0 is set and
shown as below:

Table 13.5.2a Meaning of status code ST3-0 for master, slave transmit

Code Name Code ST3-0
Transmit starts
Transmit data
Transmit ends
normally
Ends without
all data being
transmitted
(2) Master receive (receive interrupt occurs)
When the unit won the arbitration in multiaddress or master address field, it becomes master unit. Then
data, status or log address are received from slave unit, and the status code ST3-0 is set and shown as
below:
Code Name Code ST3-0
Master
receive starts
Master
receive data
full
Master
receive ends
normally
Ends without
all data being
received
MB90580 Series
Indicates start of master/slave transmission.
1) master transmit
Indicates the master address field in communication frame has been
transmitted, and the unit has won in arbitration as the master.
0000
2) slave transmit
Indicates that the unit has received control bits 0H, 3H, 4H, 5H, 6H, 7H
from the master that requests data transmission, and slave data
transmission is started.
Indicates that data is transmitting by Master unit or Slave unit. This
0001 control code will be set after the starting of telegraph length field
transmission.
Indicates that the number of data transmit specified by telegraph length
0010
field has been completed within one communication frame
Indicates that the communication has ended without transmitting the
0011 number of data specified by telegraph length field in one communication
frame.

Table 13.5.2b Meaning of status code ST3-0 for master receive

Indicates that the master has received the telegraph field correctly from
0100 the slave and master reception is started but receive interrupt does not
occur at this moment.
Indicates that the receive data buffer RDB for master reception is full
0101 (eight byte of data has been received), and the host controller is
requested to read data from the RDB.
Indicates the number of data specified by the telegraph field has been
0110
received within one communication frame.
Indicates that the communication has ended without receiving the
0111 number of data specified by telegraph length field in one communication
frame.
Content
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Chapter 13: IE Bus
13.5 Operation
177