Intel PXA26X User Manual
Page 568
16-20
Intel® PXA26x Processor Family Developer’s Manual
Network/Audio Synchronous Serial Protocol Serial Ports
5:4
R/W
FRF
FRAME FORMAT:
SELECTS which frame format to use.
0b00 – Serial Peripheral Interface*
0b01 – TI Synchronous Serial Protocol*
0b10 – Microwire*
0b11 – Programmable Serial Protocol
3:0
R/W
DSS
DATA SIZE SELECT:
Used in conjunction with EDSS to select the size of the data transmitted and
received by the SSP port. The concatenated 5-bit value of EDSS and DSS
provides a data range from four to 32-bits in length.
For the Microwire* protocol, DSS and EDSS are used to determine the
receive data size. The size of the transmitted data is either eight or 16-bits
(determined by SSCR1[MWDS]) and the EDSS bit is ignored. The EDSS
and DSS fields are ignored for Microwire* transmit data size - MWDS
(alone) configures this. However, for all modes (including Microwire*) EDSS
and DSS are used to determine the receive data size.
When data is programmed to be less than 32 bits, the FIFO must be
programmed right-justified.
EDSS DSS
Data Size
EDSS DSS
Data Size
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0b0000
0b0001
0b0010
0b0011
0b0100
0b0101
0b0110
0b0111
0b1000
0b1001
0b1010
0b1011
0b1100
0b1101
0b1110
0b1111
17-bit data
18-bit data
19-bit data
20-bit data
21-bit data
22-bit data
23-bit data
24-bit data
25-bit data
26-bit data
27-bit data
28-bit data
29-bit data
30-bit data
31-bit data
32-bit data
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0b0000
0b0001
0b0010
0b0011
0b0100
0b0101
0b0110
0b0111
0b1000
0b1001
0b1010
0b1011
0b1100
0b1101
0b1110
0b1111
Reserved, undefined
Reserved, undefined
Reserved, undefined
4-bit data
5-bit data
6-bit data
7-bit data
8-bit data
9-bit data
10-bit data
11-bit data
12-bit data
13-bit data
14-bit data
15-bit data
16-bit data
Table 16-3.
SSCR0 Bit Definitions (Sheet 2 of 2)
Physical Address
Base+0x00
SSCR0
PXA26x processor family Network/Audio
SSP Serial Ports
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Reserved
ED
SS
SC
R
SS
E
R
eser
ved
FR
F
DS
S
Reset
?
?
?
?
?
?
?
?
?
?
?
0
0
0
0
0
0
0
0
0
0
0
0
0
0
?
0
0
0
0
0
0
Bits
Access
Name
Description