mg84fl54 Megawin Technology, mg84fl54 Datasheet - Page 42

Manufacturer Part Number

mg84fl54

Description

Full-speed Usb Micro-controller

Manufacturer

Megawin Technology

Datasheet

1.MG84FL54.pdf (113 pages)

Fig 12-4 Mode 0 Transmission Waveform

Fig 12-5 Mode 0 Reception Waveform

12.2. Mode 1

10 bits are transmitted through TXD, or received through RXD: a start bit (0), 8 data bits (LSB first), and a stop

bit (1). On receive, the stop bit goes into RB8 in SCON. The baud rate is determined by the Timer 1 or Timer 2

overflow rate. Fig 12-1 shows the data frame in Mode 1 and Fig 12-6 shows a simplified functional diagram of

the serial port in Mode 1.

Transmission is initiated by any instruction that uses SBUF as a destination register. The “write to SBUF” signal

requests the UART engine to start the transmission. After receiving a transmission request, the UART engine

would start the transmission at the raising edge of TX Clock. The data in the SBUF would be serial output on the

TXD pin with the data frame as shown in Fig 12-1 and data width depend on TX Clock. After the end of 8th data

transmission, TI would be asserted by hardware to indicate the end of data transmission.

Reception is initiated when Serial Port Controller detected 1-to-0 transition at RXD sampled by RCK. The data

on the RXD pin would be sampled by Bit Detector in Serial Port Controller. After the end of STOP-bit reception,

RI would be asserted by hardware to indicate the end of data reception and load STOP-bit into RB8 in SCON

P3.0/RXD

P3.1/TXD

Write to

SCON

SBUF

Set REN, Clear RI

MG84FL54B Data Sheet

MEGAWIN