7540 datasheet(182/366 Pages) RENESAS

Part #	7540

Description	8-BIT CISC SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 740 SERIES

PDF	366 Pages

Scroll/Zoom	100%

Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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182 / 366 page

2-106

REJ09B0018-0200Z

Rev.2.00

Jun 21, 2004

APPLICATION

7540 Group

2.6 Serial I/O1

2.6.4 Application example of clock synchronous serial I/O1

For clock synchronous serial I/O1, the transmitter and the receiver use the same clock. Synchronizing with

this clock, the transmit operation of the transmitter and the receive operation of the receiver are executed

at the same time. If an internal clock is used as the operation clock, transfer is started by a write signal

to the TB/RB.

(1) Data transfer rate

The synchronous clock frequency is calculated by the following formula;

q When the internal clock is selected (when baud rate generator is used)

Synchronous clock frequency [Hz] =

Division ratio*1 : “1” or “4” is selected (set by bit 0 of serial I/O1 control register)

BRG setting value*2 : 0 to 255 (0016 to FF16) is set

q When the external clock is selected

Synchronous clock frequency [Hz] = Clock input to SCLK1 pin

f(XIN)

Division ratio *1 ✕ (BRG setting value *2 + 1) ✕ 4

7540 Datasheet(PDF) 182 Page - Renesas Technology Corp