APPENDIX
Appendix 2. Control registers
b7 b6 b5 b4 b3 b2 b1 b0
At reset R/W
UART0 transmit/receive control register 0 (Address 3416
UART1 transmit/receive control register 0 (Address 3C16
)
)
Function
Reference
Bit
0
Bit name
b1 b0
11-7
BRG count source select bits
0
0
0
1
RW
RW
RW
RO
0 0 : Clock f2
0 1 : Clock f16
1 0 : Clock f64
1 1 : Clock f512
1
2
3
0 : The CTS function is selected.
1 : The RTS function is selected.
CTS/RTS function select bit
(Note 1)
Transmit register empty flag
0 : Data is present in the transmit register.
(Transmission is in progress.)
1 : No data is present in the transmit register.
(Transmission is completed.)
0
0
0
RW
RW
RW
0 : The CTS/RTS function is enabled.
1 : The CTS/RTS function is disabled.
4
5
6
CTS/RTS enable bit
0 : Reception interrupt
1 : Reception error interrupt
UARTi receive interrupt mode
select bit
CLK polarity select bit
(This bit is used in the clock
synchronous serial I/O mode.)
(Note 2)
0 : At the falling edge of the transfer clock, transmit
data is output; at the rising edge of the transfer
clock, receive data is input.
When not in transferring, pin CLKi’s level is “H.”
1 : At the falling edge of the transfer clock, transmit
data is output; at the falling edge of the transfer
clock, receive data is input.
When not in transferring, pin CLKi’s level is “L.”
0 : LSB (Least Significant Bit) first
1 : MSB (Most Significant Bit) first
0
RW
7
Transfer format select bit
(This bit is used in the clock
synchronous serial I/O mode.)
(Note 2)
Notes 1: Valid when the CTS/RTS enable bit (bit 4) is “0” and CTSi/RTSi separate select bit (bit 0 or 1 at address AC16) is “0.”
2: Fix these bits to “0” in the UART mode or when serial I/O is disabled.
b7 b6 b5 b4 b3 b2 b1 b0
UART0 transmit/receive control register 1 (Address 3516)
UART1 transmit/receive control register 1 (Address 3D16)
Function
Bit
0
Bit name
At reset R/W
Reference
0 : Transmission disabled
1 : Transmission enabled
0
RW
Transmit enable bit
11-9
Transmit buffer empty flag
Receive enable bit
0 : Data is present in the transmit buffer register.
1 : No data is present in the transmit buffer register.
1
2
1
0
RO
0 : Reception disabled
1 : Reception enabled
RW
Receive complete flag
Overrun error flag
0 : No data is present in the receive buffer register.
1 : Data is present in the receive buffer register.
3
4
5
6
7
0
0
0
0
0
RO
RO
RO
RO
RO
0 : No overrun error
1 : Overrun error detected
Framing error flag
(Valid in UART mode)
(Note)
0 : No framing error
1 : Framing error detected
Parity error flag
(Valid in UART mode)
(Note) 0 : No parity error
1 : Parity error detected
0 : No error
1 : Error detected
Error sum flag
(Valid in UART mode)
(Note)
Note: Bits 5 to 7 are invalid in the clock synchronous serial I/O mode.
7906 Group User’s Manual Rev.2.0
20-16
RENESAS [ RENESAS TECHNOLOGY CORP ]
