at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 396

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

30.6.3.2
Figure 30-6. Master Mode Flow Diagram
396
AT91SAM9G20 Preliminary
Master Mode Flow Diagram
1
SPI_RDR(RD) = Serializer
Serializer = SPI_TDR(TD)
NPCS = SPI_TDR(PCS)
Delay DLYBCT
Delay DLYBCS
Delay DLYBS
Data Transfer
NPCS = 0xF
SPI Enable
TDRE = 1
RDRF = 1
CSAAT ?
CSAAT ?
TDRE ?
TDRE ?
0
0
1
0
PS ?
1
peripheral
Variable
0
1
1
0
NPCS = SPI_MR(PCS)
peripheral
Fixed
NPCS = SPI_TDR(PCS)
- NPCS defines the current Chip Select
- CSAAT, DLYBS, DLYBCT refer to the fields of the
- When NPCS is 0xF, CSAAT is 0.
Chip Select Register corresponding to the Current Chip Select
SPI_TDR(PCS)
Delay DLYBCS
NPCS = 0xF
= NPCS ?
no
1
PS ?
peripheral
Variable
0
yes
peripheral
Fixed
NPCS = SPI_MR(PCS),
Delay DLYBCS
SPI_MR(PCS)
NPCS = 0xF
= NPCS ?
no
SPI_TDR(PCS)
6384B–ATARM–15-Dec-08