13 UART (UART3)
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
13-1
(Rev. 2.00)
13 UART (UART3)
13.1 Overview
The UART3 is an asynchronous serial interface. The features of the UART3 are listed below.
• Includes a baud rate generator for generating the transfer clock.
• Supports 7- and 8-bit data length (LSB first).
• Odd parity, even parity, or non-parity mode is selectable.
• The start bit length is fixed at 1 bit.
• The stop bit length is selectable from 1 bit and 2 bits.
• Supports full-duplex communications.
• Includes a 2-byte receive data buffer and a 1-byte transmit data buffer.
• Includes an RZI modulator/demodulator circuit to support IrDA 1.0-compatible infrared communications.
• Can detect parity error, framing error, and overrun error.
• Can generate receive buffer full (1 byte/2 bytes), transmit buffer empty, end of transmission, parity error, framing
error, and overrun error interrupts.
• Can issue a DMA transfer request when a receive buffer
one
byte full or a transmit buffer empty occurs.
• Input pin can be pulled up with an internal resistor.
• The output pin is configurable as an open-drain output.
• Provides the carrier modulation output function.
Figure 13.1.1 shows the UART3 configuration.
Table 13.1.1 UART3 Channel Configuration of S1C31D50/D51
Item
48-pin package
64-pin package
80-pin package
100-pin package
Number of channels
3 channels (Ch.0 to Ch.2)
DMA request
control circuit
DMA controller
RB1FDMAENx
TBEDMAENx
UART3 Ch.n
Interrupt
control circuit
TENDIE
FEIE
PEIE
OEIE
RB2FIE
RB1FIE
TBEIE
TENDIF
FEIF
PEIF
OEIF
RB2FIF
RB1FIF
TBEIF
CLKSRC[1:0]
CLKDIV[1:0]
Baud rate
generator
Transmit/receive
control circuit
Receive data buffer
RXD[7:0]
Clock generator
Interrupt
controller
DBRUN
MODEN
CLK_UART3_n
Shift register
RZI demodulator
Transmit data buffer
TXD[7:0]
Shift register
RZI modulator
Carrier modulator
PUEN
STPB
OUTMD
IRMD
INVTX
INVRX
SFTRST
RBSY
TBSY
PRMD
PREN
CHLN
FMD[3:0]
BRT[7:0]
BRDIV
USINn
USOUTn
Inter
nal data
bu
s
PECAR
CAREN
CRPER[7:0]
Figure 13.1.1 UART3 Configuration