Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Data Sheet

32072H–AVR32–10/2012

Figure 21-6. Master Mode Flow Diagram

SPI Enable

CSAAT ?

PS ?

1

0

0

1

1

NPCS = TDR(PCS)

NPCS = MR(PCS)

Delay DLYBS

Serializer = TDR(TD)

TDRE = 1

Data Transfer

RDR(RD) = Serializer

RDRF = 1

TDRE ?

NPCS = 0xF

Delay DLYBCS

Fixed

 peripheral

Variable 

peripheral

Delay DLYBCT

0

1

CSAAT ?

0

TDRE ?

1

0

PS ?

0

1

TDR(PCS)

= NPCS ?

no

yes

MR(PCS)

= NPCS ?

no

NPCS = 0xF

Delay DLYBCS

NPCS = TDR(PCS)

NPCS = 0xF

Delay DLYBCS

NPCS = MR(PCS),

                TDR(PCS) 

Fixed

 peripheral

Variable 

peripheral

- NPCS defines the current Chip Select
- CSAAT, DLYBS, DLYBCT refer to the fields of the 
  Chip Select Register corresponding to the Current Chip Select
- When NPCS is 0xF, CSAAT is 0.