414 Preliminary User’s Manual S15543EJ1V0UM
CHAPTER 8 UART8.1 Overview

UART is a serial interface that conforms to the RS-232C communication standard and is equipped with two one-

channel interfaces, one for transmission and one for reception. This unit is functionally compatible with the

NS16550D.

8.2 UART Block Diagram
DATA
BUS
BUFFER RECEIVER
BUFFER
REGISTER
LINE
CONTROL
REGISTER
DIVISOR
LATCH(LS)
DIVISOR
LATCH(MS)
LINE
STATUS
REGISTER
TRANSMITTER
HOLDING
REGISTER
MODEM
CONTROL
REGISTER
INTERR UPT
ENABLE
REGISTER
INTERR UPT
ID
REGISTER
FIFO
CONTROL
REGISTER
TRANSMITTER
SHIFT
REGISTER
TRANSMITTER
TIMING
CONTROL
RECEIVER
TIMING
CONTROL
RECEIVER
SHIFT
REGISTER
RECEIVER
FIFO
TRANSMITTER
FIFO
INTERR UPT
CONTROL
LOGIC
MODEM
CONTROL
LOGIC
BAUD
GENERATOR
S
E
L
S
E
L
MODEM
CONTROL
REGISTER

URSDI

URCLK

URSDO

URRTS_B

URCTS_B

URDTR_B

URDSR_B

URDCD_B

INTPR

(to VR4120A)