MITSUBISHI MICROCOMPUTERS
M37754M8C-XXXGP, M37754M8C-XXXHP
M37754S4CGP, M37754S4CHP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Selection of transfer format
In clock synchronous serial communication, transfer format can be
selected by bit 7 of the Transmit/Receive control register 0. When bit
7 is “0”, transfer format is LSB first. When bit 7 is “1”, transfer format
is MSB first.
transmit buffer register and the receive buffer register when writing
transmit data to the transmit buffer register or reading receive data
from the receive buffer register. Accordingly, the transmitter’s opera-
tion is the same in both transfer formats.
This function is realized by changing connection relation between the
Figure 64 shows the connection relation.
Bit 7 in Transmit/Receive
control register 0
Write to transmit
buffer register
Read from receive
buffer register
Transmit buffer
register
Receive buffer
register
Data bus
DB7
Data bus
DB7
D7
D7
D6
D5
D4
D3
D2
D1
D0
DB6
D6
D5
D4
D3
D2
D1
D0
DB6
DB5
DB5
0
(LSB first)
DB4
DB4
DB3
DB3
DB2
DB2
DB1
DB1
DB0
DB0
Transmit buffer
register
Receive buffer
register
Data bus
DB7
Data bus
DB7
D7
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
DB6
DB6
DB5
DB5
1
(MSB first)
DB4
DB4
DB3
DB3
DB2
DB2
DB1
DB1
DB0
DB0
Fig. 64 Connection relation between transmit buffer register, receive buffer register, and data bus
52
RENESAS [ RENESAS TECHNOLOGY CORP ]
