Preliminary and proprietary Information of YAMAR Electronics Ltd. Subject to change without notice.
Transmitted command
Sync break
Sync Field
P1, P0, 0, 1, Address
Out [7:0]
Checksum
3 bit delay
SIG61 Outputs at receiving device
Figure 4.1 -
Write
command
Command type 2: Read command.
The
Read
command, initiated by the Master, requests the status of the SIG61 input pins.
The
Read
command from the master consists of 3 bytes: sync break, sync field and identifier. The
identifier of this command begins with the four-bit ID of the device, followed by “01”, and finally 2
protection bits. The two protection bits are calculated as described above.
If header detection is correct (including protection bits), the SIG61 device (whose ID matches the one in
the command) shall respond by sending two bytes. A data byte containing the status of its eight input
Signal pins followed by a checksum byte. The checksum calculation is carried out as in the description
above while part of it, the identifier byte, was transmitted by the Master. Figure 4.2 shows a generic
Read
command.
Sync break
Sync Field
P1, P0, 0, 0, Address
Data (8 input bits)
Checksum
Master
Slave
Figure 4.2 -
Read
command
Command type 3: Read-change
The
Read-change
command is similar to the
Read
command. However, it enables to detect any change
in the input pins (pulse-like behavior) that may have occurred between two consecutive
Read
or
Read-
change
commands. The command from the master instructs the SIG61 to send back information on
changes of its input pins since the last
Read
or
Read-change
command. The first change on the pin
after the
Read
command sets its bit value.
Figure 4.3 shows the process of determining the sent bit value of an input pin.
“1”
“1”
“0”
“0”
Sent value
Change
Input pin level
Read -change
command
1 bit
Figure 4.3 - Determining the recent changed value of an input pin
The
Read-change
command from the master has 3 bytes: sync break, sync field and identifier.
The identifier begins with the destination device four-bit ID, followed by 10 and terminating with 2
protection bits. The response for this command is a data byte containing the SIG61`s input pins recent
changed value, followed by the checksum byte. See checksum and protection bits calculation
description above. Figure 4.4 shows a
Read-changes
command.
© 2010 Yamar Electronics Ltd.
9
DS-SIG61 R0.932
YAMAR [ YAMAR ELECTRONICS LTD. ]
