Multi-Controller System - Toshiba TMPR4925 Manual

11.3.12 Multi-Controller System

The Multi-Controller System consists of one Master Controller, and multiple Slave Controllers as
shown below in Figure 11.3.4.
In the case of the Multi-Controller System, the Master Controller transmits an address (ID) frame to
all Slave Controllers, then transmits and receives data with the selected Slave Controller. Slave
Controllers that were not selected will ignore this data.
Data frames whose data frame Wake Up bits (WUB) are "1" are handled as address (ID) frames. Data
frames whose Wake Up bit (WUB) is "0" are handled as data frames.
TXD
RXD
Figure 11.3.4 Example Configuration of Multi-Controller System
The data transfer procedure for the Multi-Controller System is as follows.
(1) The Master and Slave Controllers set the Mode field (UMODE) of the Line Control Register
(SILCR) to "10" or "11" to set the Multi-Controller System mode. Also, the Slave Controller sets
the open drain enable bit (UODE) of the Line Control Register (SILCR), setting the TXD output
signal to open drain output.
(2) The Slave Controller sets the Reception Wake Up bit (RWUB) of the Line Control Register
(SILCR), making it possible to receive address (ID) frames from the Master Controller.
(3) The Master Controller sets the Transmission Wake Up bit (TWUB) of the Line Control Register
(SILCR), and transmits the address (ID) of the selected Slave Controller. This causes the address
(ID) frame to be transmitted. The Reception after Address Transmission Wake Up bit (RWUB) is
cleared, enabling reception of data frames.
(4) Since the Reception Wake Up bit (RWUB) is set, the Slave Controller generates an interrupt to the
CPU by receiving an address (ID) frame. The CPU compares its own address (ID) and the received
data together. If they match, the Reception Wake Up bit (RWUB) is cleared, making data frame
reception possible.
(5) The Master Controller and the selected Slave Controller clear the Transmission Wake Up bit
(TWUB) of the Line Control Register (SILCR), then set the mode that transmits data frames.
(6) Transmit/Receive data between the Master Controller and the selected Slave Controller. Then,
Slave Controllers that were not selected ignore data frames since the Reception Wake Up bit
(RWUB) is still set.
Master
RXD
TXD RXD
Slave #1 Slave #2
11-12
Chapter 11 Serial I/O Port
TXD RXD TXD
Slave #3