R5F21133DFP RENESAS [Renesas Technology Corp], R5F21133DFP Datasheet - Page 120

• Manufacturer Part Number: R5F21133DFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY/R8C/Tiny SERIES
• Manufacturer: RENESAS [Renesas Technology Corp]

R8C/13 Group
Rev.1.20
REJ09B0111-0120
13. Serial Interface
Figure 13.1 UARTi (i=0, 1) Block Diagram
Serial interface is configured with two channels: UART0 to UART1. UART0 and UART1 each have an
exclusive timer to generate a transfer clock, so they operate independently of each other.
Figure 13.1 shows a block diagram of UARTi (i=0, 1). Figure 13.2 shows a block diagram of the UARTi
transmit/receive.
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 I/O mode (UART mode).
Figures 13.3 to 13.5 show the UARTi-related registers.
(UART1)
CLK
(UART0)
CLK
CLK
RxD
RxD
1
f
f
f
1
f
f
f
1SIO
8SIO
32SIO
Jan 27, 2006
to CLK
1
0
1SIO
8SIO
32SIO
0
to CLK
0
=01
=10
=00
0
=01
reversing
=10
=00
polarity
circuit
2
2
CLK
2
2
2
2
Internal
Internal
TXD1EN
External
Clock synchronous type
(when internal clock is selected)
page 109 of 205
Main clock or on-chip oscillator clock
U0BRG register
1/(n0+1)
1/(n1+1)
U1BRG
register
1/16
1/16
1/2
1/16
1/16
Clock synchronous
type
UART reception
UART transmission
Clock synchronous
type
Clock synchronous type
(when internal clock is selected)
Clock synchronous type
(when external clock is selected)
UART transmission
UART reception
1/8
Transmission control
control circuit
CKDIR=0
CKDIR=1
Reception
control circuit
Transmission
control circuit
Reception
circuit
1/4
Transmission
control circuit
control circuit
Receive
clock
Transmit
clock
Reception
f
f
f
8SIO
32SIO
1SIO
Transmit/
Transmit/
receive
receive
unit
unit
TXD1SEL=1
To P0
TXD1SEL=0
13. Serial Interface
0
TxD
0
TxD
TxD
11
10