Atmel SAM4S Xplained Pro Starter and Evaluation Kit ATSAM4S-XPRO ATSAM4S-XPRO Data Sheet
Product codes
ATSAM4S-XPRO
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
682
33.8.2 SPI Mode Register
Name:
SPI_MR
Address:
0x40008004
Access:
Read-write
This register can only be written if the WPEN bit is cleared in
MSTR: Master/Slave Mode
0: SPI is in Slave mode.
1: SPI is in Master mode.
1: SPI is in Master mode.
PS: Peripheral Select
0: Fixed Peripheral Select.
1: Variable Peripheral Select.
1: Variable Peripheral Select.
PCSDEC: Chip Select Decode
0: The chip selects are directly connected to a peripheral device.
1: The four NPCS chip select lines are connected to a 4- to 16-bit decoder.
When PCSDEC equals one, up to 15Chip Select signals can be generated with the four NPCS lines using an external 4- to
1: The four NPCS chip select lines are connected to a 4- to 16-bit decoder.
When PCSDEC equals one, up to 15Chip Select signals can be generated with the four NPCS lines using an external 4- to
16-bit decoder. The Chip Select registers define the characteristics of the 15 chip selects, with the following rules:
SPI_CSR0 defines peripheral chip select signals 0 to 3.
SPI_CSR1 defines peripheral chip select signals 4 to 7.
SPI_CSR2 defines peripheral chip select signals 8 to 11.
SPI_CSR3 defines peripheral chip select signals 12 to 14.
SPI_CSR1 defines peripheral chip select signals 4 to 7.
SPI_CSR2 defines peripheral chip select signals 8 to 11.
SPI_CSR3 defines peripheral chip select signals 12 to 14.
MODFDIS: Mode Fault Detection
0: Mode fault detection is enabled.
1: Mode fault detection is disabled.
1: Mode fault detection is disabled.
WDRBT: Wait Data Read Before Transfer
0: No Effect. In Master mode, a transfer can be initiated regardless of the SPI_RDR state.
1: In Master mode, a transfer can start only if the SPI_RDR is empty, i.e. does not contain any unread data. This mode pre-
1: In Master mode, a transfer can start only if the SPI_RDR is empty, i.e. does not contain any unread data. This mode pre-
vents overrun error in reception.
LLB: Local Loopback Enable
0: Local loopback path disabled.
31
30
29
28
27
26
25
24
DLYBCS
23
22
21
20
19
18
17
16
–
–
–
–
PCS
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
–
7
6
5
4
3
2
1
0
LLB
–
WDRBT
MODFDIS
–
PCSDEC
PS
MSTR