at91sam9260-cj ATMEL Corporation, at91sam9260-cj Datasheet - Page 383

• Manufacturer Part Number: at91sam9260-cj
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

• SCBR: Serial Clock Baud Rate
In Master Mode, the SPI Interface uses a modulus counter to derive the SPCK baud rate from the Master Clock MCK. The
Baud rate is selected by writing a value from 1 to 255 in the SCBR field. The following equations determine the SPCK baud
rate:
Programming the SCBR field at 0 is forbidden. Triggering a transfer while SCBR is at 0 can lead to unpredictable results.
At reset, SCBR is 0 and the user has to program it at a valid value before performing the first transfer.
• DLYBS: Delay Before SPCK
This field defines the delay from NPCS valid to the first valid SPCK transition.
When DLYBS equals zero, the NPCS valid to SPCK transition is 1/2 the SPCK clock period.
Otherwise, the following equations determine the delay:
6221G–ATARM–31-Jan-08
Delay Before SPCK
SPCK Baudrate
BITS
1101
1110
1111
=
-------------- -
SCBR
MCK
=
DLYBS
------------------ -
MCK
Bits Per Transfer
Reserved
Reserved
Reserved
AT91SAM9260
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