Renesas R8C/20 User Manual

R8C/20 Group, R8C/21 Group 15. Serial Interface
Rev.2.00 Aug 27, 2008 Page 265 of 458
REJ09B0250-0200
15. Serial Interface
Serial Interface is configured with two channels: UART0 and UART1. Each UART0 and Uart1 has an exclusive timer
to generate a transfer clock and they operate independently.
Figure 15.1 shows the UARTi (i = 0 or 1) Block Diagram. Figure 15.2 shows the UARTi (i = 0 or 1) Transmit/Receive
Unit.
UART0 has two modes: clock synchronous serial I/O mode, and clock asynchronous serial I/O mode (UART mode).
UART1 has only one mode: clock asynchronous serial interface mode (UART mode).
Figures 15.3 to 15.6 show the Registers Associated with UARTi.
Figure 15.1 UARTi (i = 0 or 1) Block Diagram
= 01b
f8
f1
= 10b
CLK1 to CLK0
RXD0
f32
1/16
1/16
1/2
1/(n0 + 1)
UART reception
UART transmission
Clock synchronous type
(when internal clock is selected)
Clock
synchronous type
Reception control
circuit
Transmission
control circuit
CKDIR = 0
CKDIR = 1
Receive
clock
Transmit
clock
Transmit/
receive
unit
U0BRG register
CKDIR = 0
Internal
External
CKDIR = 1
(UART0)
TXD0
CLK
polarity
reversing
circuit
CLK0
Clock
synchronous type
Clock synchronous type
(when external clock is selected)
Clock synchronous type
(when internal clock is selected)
= 00b
= 01b
f8
f1
= 10b
CLK1 to CLK0
RXD1
f32
1/16
1/161/(n1 + 1)
Transmit/
receive
unit
U1BRG register
Internal
(UART1)
TXD1
U1PINSEL
Reception control
circuit
Transmission
control circuit
UART reception
UART transmission
Receive
clock
Transmit
clock
= 00b

Renesas R8C/20 Specifications

General

Brand	Renesas
Model	R8C/20
Category	Control Unit
Language	English