m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 309

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

SERIAL I/O
11.4 Clock asynchronous serial I/O (UART) mode
Fig. 11.4.14 Sleep mode
11-54
11.4.8 Sleep mode
This mode is used to transfer data between the specified microcomputers, which are connected by using
UARTi. The sleep mode is selected by setting the sleep select bit (bit 7 at addresses 30
to “1” when receiving.
In the sleep mode, receive operation is performed when the MSB (D
D
performed when the MSB is “0.” (The UARTi receive register’s contents are not transferred to the UARTi
receive buffer register. Additionally, the receive complete flag and each error flag do not change, and no
UARTi receive interrupt request occurs.)
The following shows an usage example of the sleep mode when the transfer data = 8-bit length.
7
sure to select the sleep mode for the slave microcomputers.
• Bit 7 = “1”
• Bits 6 to 0 indicate the address of the slave microcomputer to be communicated
request occurs.)
By performing steps
Be sure to set the same transfer data format for the master and slave microcomputers. Additionally, be
Each slave microcomputer receives the data described in step
Be sure to check for each slave microcomputer, in the interrupt routine, whether bits 6 to 0 of the receive
By repeating step
Then, transmit the data, of which structure is as follows, from the master microcomputer:
data match its own address.
For the slave microcomputer of which address matches bits 6 to 0 of the receive data, terminate the
Transmit the data of which bit 7 = “0” from the master microcomputer. (Only one slave microcomputer
sleep mode. (Do not terminate the sleep mode for the other slave microcomputers.)
specified in steps
communicating with another slave microcomputer, perform steps
slave microcomputer.
when it is 8-bit length, D
Slave A
, continuous transfer can be performed between two specific microcomputers. When
to
to
6
can receive this data. The other microcomputers do not receive this data.)
when it is 7-bit length) of the receive data is “1.” Receive operation is not
, “the microcomputer which performs transfer” is specified.
Slave B
7905 Group User’s Manual Rev.1.0
Master
Slave C
Data is transferred between the master
microcomputer and one specific slave microcomputer
selected from multiple slave microcomputers.
. (At this time, a UARTi receive interrupt
8
when the transfer data = 9-bit length,
to
Slave D
in order to specify the new
16
, 38
16
and B0
16
)