AT32UC3A3256S_2 Datasheet, PDF (425/1014 Pages) ATMEL Corporation – 32-bit AVR®Microcontroller

AT32UC3A3/A4
• BITS: Bits Per Transfer
The BITS field determines the number of data bits transferred. Reserved values should not be used.
BITS
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Bits Per Transfer
8
9
10
11
12
13
14
15
16
4
5
6
7
Reserved
Reserved
Reserved
• CSAAT: Chip Select Active After Transfer
1: The Peripheral Chip Select does not rise after the last transfer is achieved. It remains active until a new transfer is requested
on a different chip select.
0: The Peripheral Chip Select Line rises as soon as the last transfer is achieved.
• CSNAAT: Chip Select Not Active After Transfer (Ignored if CSAAT = 1)
0: The Peripheral Chip Select does not rise between two transfers if the TDR is reloaded before the end of the first transfer and
if the two transfers occur on the same Chip Select.
1: The Peripheral Chip Select rises systematically between each transfer performed on the same slave for a minimal duration of:
D_-----L_----Y_----B_----C_----S_{- (if DLYBCT field is different from 0)}
CLKSPI
D_-----L_----Y_----B_----C_----S_-----+----1_{-- (if DLYBCT field equals 0)}
CLKSPI
• NCPHA: Clock Phase
1: Data is captured after the leading (inactive-to-active) edge of SPCK and changed on the trailing (active-to-inactive) edge of
SPCK.
0: Data is changed on the leading (inactive-to-active) edge of SPCK and captured after the trailing (active-to-inactive) edge of
SPCK.
NCPHA determines which edge of SPCK causes data to change and which edge causes data to be captured. NCPHA is used
with CPOL to produce the required clock/data relationship between master and slave devices.
• CPOL: Clock Polarity
1: The inactive state value of SPCK is logic level one.
0: The inactive state value of SPCK is logic level zero.
32072C–AVR32–2010/03
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