Renesas M16C FAMILY, User Manual

Page: 62 / 369

Rev.2.00 Oct 16, 2006 page 51 of 354
REJ09B0340-0200
M30245 Group 2. Clock-Synchronous Serial I/O
Figure 2.3.9. Set-up procedure of reception in clock-synchronous serial I/O mode (1)
Continued to the next page
Setting UART transmit/receive control register 1 (i=0 to 3)
Setting UARTi transmit/receive mode register (i=0 to 3)
Internal/external clock select bit
1 : External clock (Note)
Must be fixed to “001” (Serial I/O mode)
Set the RxDi pin's port direction register to “0” when receiving.
0
Invalid in clock synchronous I/O mode
Invalid in clock synchronous I/O mode
Invalid in clock synchronous I/O mode
UARTi transmit/receive mode register
UiMR [Address 03A8
16
, 368
16
, 0338
16
, 328
16
]
1 0 0 1
T
X
D, R
X
D I/O polarity reverse bit
Usually set to “0”
Setting UARTi transmit/receive control register (i=0 to 3)
CTS/RTS function select bit
(Valid when bit 4 = “0”)
1 : RTS function is selected
BRG count source select bit
b1 b0
0 0 : f
1
is selected
0 1 : f
8
is selected
1 0 : f
32
is selected
1 1 : Inhibited
Transmit register empty flag
0 : Data present in transmit register
(during transmission)
1 : No data present in transmit register
(transmission completed)
Data output select bit (Note)
0 : TxDi/SDAi and SCLi pin is CMOS output
1 : TxDi/SDAi and SCLi pin is N-channel open drain output
CLK polarity select bit
0 : Transmission data is output at falling edge
of transfer clock and reception data is input
at rising edge
CTS/RTS disable bit
0 : CTS/RTS function enabled
UARTi transmit/receive control register 0
UiC0 [Address 03AC
16
, 36C
16
, 033C
16
, 32C
16
]
Transfer format select bit
0 : LSB first
0 0 0 1
Note: UART2 transfer pin (TxD
2
: P7
0
and SCL
2
: P7
1
) is N-channel open drain output.
It cannot be set to CMOS output.
Note: Set the corresponding port direction register to “0”.
b7 b0
b7 b0
Data logic select bit
0 : No reverse
Set to “0” in clock synchronous serial I/O mode
0 0
b7 b0
0
UARTi transmit/receive control register 1
UiC1 [Address 03AD
16
, 36D
16
, 033D
16
, 32D
16
]
UARTi continuous receive mode enable bit
0 : Continuous receive mode disabled