7702 Datasheet, PDF (199/522 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER

SERIAL I/O
7.4 Clock asynchronous serial I/O (UART) mode
7.4 Clock asynchronous serial I/O (UART) mode
Table 7.4.1 lists the performance overview in the UART mode, and Table 7.4.2 lists the functions of
I/O pins in this mode.
Table 7.4.1 Performance overview in UART mode
Item
Functions
Transfer data
format
Start bit
1 bit
Character bit (Transfer data) 7 bits, 8 bits, or 9 bits
Parity bit
0 bit or 1 bit (Odd or even can be selected.)
Stop bit
1 bit or 2 bits
Transfer rate _{When selecting internal clock Clock of BRGi output divided by 16}
When selecting external clock Maximum 312.5 kbps (f(XIN) = 25 MHz)
Maximum 250 kbps (f(XIN) = 16 MHz)
Maximum 125 kbps (f(XIN) = 8 MHz)
Error detection
4 types (Overrun, Framing, Parity, and Summing)
Presence of error can be detected only by checking error sum flag.
Table 7.4.2 Functions of I/O pins in UART mode
Pin name
Functions
Method of selection
TxDi (P83, P87)
Serial data output
Fixed
RxDi (P82, P86)
Serial data input
Port P8 direction register^U1’s corresponding bit = “0”
CLKi (P81, P85)
BRGi’s count source Internal/External clock select bit^U2 = “1”
___ ___
CTSi/RTSi (P80, P84)
input
____
CTS input
____
RTS output
____ ____
CTS/RTS select bit^U3 = “0”
____ ____
CTS/RTS select bit = “1”
Port P8 direction register^U1: Address 1416
Internal/External
____ ____
clock
select
bit^U2:
bit
3
at
addresses
3 0 16,
3816
CTS/RTS select bit^U3: bit 2 at addresses 3416, 3C16
Notes 1: The TxDi pin outputs “H” level while not transmitting after selecting UARTi’s operating mode.
2: The RxDi pin can be used as a programmable I/O port when performing only transmission.
3:
The
C_{__}L_{_}Ki
pin can
___
be
used
as
a
programmable
I/O
port
when
selecting
internal
clock.
___
4: The CTSi/RTSi pin can be _{_}u_{_}s_{_}ed as a input port when performing only reception and not using RTS
function (when selecting CTS function).
7702/7703 Group User’s Manual
7–35