Renesas rl78 User Manual

 

RL78/G1A 

 

CHAPTER  12   SERIAL  ARRAY  UNIT 

R01UH0305EJ0200  Rev.2.00 

 

 

492  

Jul 04, 2013 

 

 

Starting CSI communication

Write 1 to STmn bit 

Transmission/reception 

next data? 

Yes 

No 

End of communication 

Reading receive data 

from SIOp (=SDRmn[7:0])

Transmission/reception 

completed? 

No 

Yes 

Writing transmit data to 

SIOp (=SDRmn[7:0]) 

Start communication when master start providing the 

clock

 

When transfer end interrupt is generated, it moves to 

interrupt processing routine

 

Wait for transmission/reception 

completes

 

For the initial setting, see Figure 12-64. 

(Select Transfer end interrupt)

 

SAU default setting

 

Setting 

transmission/reception data

Setting storage area and number of data for transmission/reception data 

(Storage area, Transmission/reception data pointer, Number of communication data 

and Communication end flag are optionally set on the internal RAM by the software) 

RETI 

Transfer end interrupt

 

Enables interrupt 

Clear interrupt request flag (XXIF), reset interrupt mask (XXMK) and set 

interrupt enable (EI).

 

Disable interrupt (MASK)

Read receive data and write it to storage area.    Update 

receive data pointer.

 

Update the number of communication data and confirm 

if next transmission/reception data is available 

 

Read transmit data from storage area and write it to SIOp. 

Update transmit data pointer. 

M

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in

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u

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M

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Inter

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ing
routine

 

Caution  Be sure to set transmit data to the SlOp register before the clock from the master is started. 
 

Remark  m: Unit number (m = 0, 1), n: Channel number (n = 0 to 3), p: CSI number (p = 00, 01, 10, 11, 20, 21), 

mn = 00 to 03, 10, 11 

 

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