
NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 547 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
SPI n Slave Select Register (SPIn_SSR)
Register
Offset
R/W
Description
Reset Value
SPIn_SSR
n=0,1
0x008
R/W
SPI n Slave Select Register
0x0000_0000
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
Reserved
7
6
5
4
3
2
1
0
Reserved
AUTOSS
SS_LVL
SSR
Bits
Description
[3]
AUTOSS
Automatic Slave Select Function Enable Control
0 = Automatic slave select function Disabled.
1 = Automatic slave select function Enabled.
[2]
SS_LVL
Slave Select Active Level
0 = The slave select signal mw_ss_o is active on low-level.
1 = The slave select signal mw_ss_o is active on high-level.
[1:0]
SSR
Slave Select Register
If SSR[ASS] bit =0,.
0 = sets the line back to inactive state.
1 = sets the proper mw_ss_o line to an active state.
If SSR[ASS] bit =1,.
0 = The controller will be driven to inactive state for the rest of the time.
1 = select appropriate mw_ss_o line to be automatically driven to active state for the
duration of transmit/receive.
NOTE:
This interface can only drive one device/slave at a given time. Therefore, the slave
select of the selected device must be set to its active level before starting any read or write
transfer.
NOTE:
(The active level of mw_ss_o is specified in SSR[SS_LVL]).