Advanced PMBus GUI description
UM0718
24/31
Doc ID 15846 Rev 1
3.7
Manual command window
The manual command window can be opened by either clicking on the manual command
window icon or by following Operation-> Manual Command Window.
Manual commands can be classified in two types:
1.
Single command (Receive/Send Byte, Read/ Write Byte, Read/ Write Word, Read/
Write Block)
2. Group
command
The Device address allows the user to enter the slave address. This field must be filled with
the address of the selected slave.
The command ID field allows the user to write any PMBus command. To know the PMBus
command code, please refer to the relevant datasheets for PMBus specifications or PMBus
compatible products. As soon as the command ID is entered, the command type field and
command description are automatically selected by the GUI.
The data field allows the user to enter the data in the case of write commands and shows
the data received from the board in the case of read commands. This field automatically
selects the length in accordance to the command ID entered and doesn’t allow the user to
enter data beyond the data length mentioned in the PMBus specification.
The read/write button allows the user to read/write the command accordingly.
The command description field describes the command and is read only. In the case of an
unsupported command, it shows the unknown command in the box and is read only.
3.7.1 Single
command
In the case of a single command, the user is able to read and write PMBus commands. The
command is sent to the PMBus slave as soon as the user selects the read/write button. If
the command is read only, the write button is disabled.
3.7.2 Group
command
In the case of a group command, the user is only allowed to write the PMBus commands.
The send group command button allows the group command to be sent, as mentioned in
the PMBus specification. The group command protocol is used to send commands to more
than one PMBus device. The commands are sent in one transmission. To terminate the
group command, it is necessary to check the box against the last group command and press
the send group command with the last command and data filled. If this box is not checked,
the data is treated as either single command or group command. During group command,
the received slave addresses, command codes, and data from the GUI are buffered by the
MCU firmware. After the last command of the group command is sent from the GUI, all
buffered data are transmitted from master to slave.
www.BDTIC.com/ST
