HD6433713 datasheet(195/324 Pages) RENESAS

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Set bit SMR16 in SMR1 to 1 or 0, and set bits SMR15 and SMR14 to a value other than 00,

designating 8- or 16-bit transfer mode. Select the serial clock with bits SMR13 to SMR10.

Writing data to SMR1 initializes the internal state of SCI1.

•

Write transmit data in serial data register L1 (SDRL1) and serial data register U1

(SDRU1), as follows.

8-bit transfer mode:

SDRL1

16-bit transfer mode: Upper byte in SDRU1, lower byte in SDRL1

•

Execute a dummy read of SMR1. SCI1 starts operating, and outputs the transmit data at pin

SO1.

•

After data transmission is complete, bit IRRS1 in interrupt request register 3 (IRR3) is

set to 1.

When an internal clock source is used, a serial clock is output from pin SCK1 in synchronization

with the transmit data. After data transmission is complete, the serial clock is not output until the

next dummy read of SMR1. During this time, pin SO1 continues to output the value of the last bit

transmitted.

When an external clock source is used, data is transmitted in synchronization with the serial clock

input at pin SCK1. After data transmission is complete, if the serial clock continues to be input,

transmission resumes.

Between transmissions, the output value of pin SO1 can be changed by rewriting bit 7 (SO1 LAST

BIT) in serial port register 1 (SPR1).

Executing a dummy read of SMR1 during transmission will cause a transmit error, setting bit

IRRS1 in IRR3 to 1.

Receiving

A receive operation is carried out as follows.

•

Set bit SI1 in port mode register 2 (PMR2) to 1, making pin P92/SI1 the SI1 input pin. Also

set bit SCK1 in PMR2 to 1, making pin P91/SCK1 the SCK1 I/O pin.

•

Set bit SMR16 in serial mode register 1 (SMR1) to 1 or 0, and set bits SMR15 and SMR14 to

a value other than 00, designating 8- or 16-bit transfer mode. Select the serial clock with bits

SMR13 to SMR10. Writing data to SMR1 initializes the internal state of SCI1.

•

Execute a dummy read of SMR1. SCI1 starts operating, and receive data is input at pin SI1.

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HD6433713 Datasheet(PDF) 195 Page - Renesas Technology Corp