Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK データシート

製品コード
AT91SAM9N12-EK
ページ / 1104
633
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
36.8.1 SPI 
Control 
Register
Name: SPI_CR
Addresses:
0xF0000000 (0), 0xF0004000 (1)
Access: 
Write-only
• SPIEN: SPI Enable
0 = No effect.
1 = Enables the SPI to transfer and receive data.
• SPIDIS: SPI Disable
0 = No effect.
1 = Disables the SPI.
As soon as SPIDIS is set, SPI finishes its transfer.
All pins are set in input mode and no data is received or transmitted.
If a transfer is in progress, the transfer is finished before the SPI is disabled.
If both SPIEN and SPIDIS are equal to one when the control register is written, the SPI is disabled.
• SWRST: SPI Software Reset
0 = No effect.
1 = Reset the SPI. A software-triggered hardware reset of the SPI interface is performed.
The SPI is in slave mode after software reset. 
• LASTXFER: Last Transfer
0 = No effect.
1 = The current NPCS will be deasserted after the character written in TD has been transferred. When CSAAT is set, this allows 
to close the communication with the current serial peripheral by raising the corresponding NPCS line as soon as TD transfer has 
completed. 
Refer to 
for more details.
31
30
29
28
27
26
25
24
LASTXFER
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
SWRST
SPIDIS
SPIEN