IBM EM78P312N manual Bit Microcontroller, Bit 5 ~ Bit 3 BRS0 ~ BRS2 SPI Clock Source Select

Models: EM78P312N

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Bit 5 ~ Bit 3 ( BRS0 ~ BRS2 ) : SPI Clock Source Select

EM78P312N

8-Bit Microcontroller

In using the external clock, data input sample is fixed at the middle of data output time.

Bit 6 ( DCOL ) : SPI Data collision.

DCOL = “0” : No occurrence of Data collision

DCOL = “1” : Data collision occurred. It should be cleared by software.

Bit 5 ~ Bit 3 ( BRS0 ~ BRS2 ) : SPI Clock Source Select

BRS2

 

BRS1

 

BRS0

 

Clock Source

Max. Transfer Rate

 

 

 

( Normal, Idle )

( Fc = 8MHz )

 

 

 

 

 

 

0

 

0

 

0

 

Fc/213

0.95Kbit/s

0

 

0

 

1

 

Fc/211

3.8Kbit/s

0

 

1

 

0

 

Fc/210

7.6Kbit/s

0

 

1

 

1

 

Fc/28

30.5Kbit/s

1

 

0

 

0

 

Fc/26

122Kbit/s

1

 

0

 

1

 

Fc/25

244Kbit/s

1

 

1

 

0

 

External clock (/SCK pin)

Enable /ss pin

 

 

 

 

 

 

 

 

1

 

1

 

1

 

External clock (/SCK pin)

Disable /ss pin

 

 

 

 

 

 

 

 

Bit 2 ( EDS ) : Data shift out edge select.

EDS = “0” : Rising edge

EDS = “1” : Falling edge

Bit 1 ( DORD ) : Data transmission order.

DORD = “0” : Shift left (MSB first)

DORD = “1” : Shift right (LSB first)

Bit 0 ( WBE ) : Write buffer empty flag. Read only.

WBE = “0” : Write buffer empty

WBE = “1” : Not empty, set to “1” automatically when writing data to the data buffer.

Bank 3 R6 SPIC2 (SPI Control Register 2)

Bit 7

Bit 6

Bit 5

Bit 4

 

 

 

 

Bit 3

Bit 2

Bit 1

Bit 0

SPIS

0

0

0

0

SPIM1

SPIM0

RBF

Bit 7 ( SPIS ) : SPI start shift, set the bit to “1” and shift register starts to shift. It is cleared by hardware when shifting is finished. In transferring the next data, it must be set to “1” again.

SPIS = “0” : Finish shifting

SPIS = “1” : Start shifting

Product Specification (V1.0) 10.03.2006

17

(This specification is subject to change without further notice)

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IBM EM78P312N Bit Microcontroller, Bit 5 ~ Bit 3 BRS0 ~ BRS2 SPI Clock Source Select, Bank 3 R6 SPIC2 SPI Control Register