Ssp Control Register 1 (Sscr1) - Intel PXA255 Developer's Manual

Network SSP Serial Port
Table 16-3. SSCR0 Bit Definitions (Sheet 2 of 2)
0x4140_0000
31 30 29 28 27 26 25 24 23 22 21
reserved
? ? ? ? ? ?
Bits Name
3:0
16.5.2

SSP Control Register 1 (SSCR1)

SSCR1, shown in
enabling the port (using SSCR0[SSE]), the desired values for this register must be set.
These are read/write registers. Ignore reads from reserved bits. Write zeros to reserved bits.
16-20
20 19 18 17 16 15 14 13 12
? ? ? ? ? 0
DATA SIZE SELECT:
Used in conjunction with EDSS to select the size of the data transmitted and received by the
SSP. 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
1 0b0000 17-bit data
1 0b0001 18-bit data
1 0b0010 19-bit data
DSS
1 0b0011 20-bit data
1 0b0100 21-bit data
1 0b0101 22-bit data
1 0b0110 23-bit data
1 0b0111 24-bit data
1 0b1000 25-bit data
1 0b1001 26-bit data
1 0b1010 27-bit data
1 0b1011 28-bit data
1 0b1100 29-bit data
1 0b1101 30-bit data
1 0b1110 31-bit data
1 0b1111 32-bit data
Table 16-4, contains bit fields that control various SSP functions. Before
SSCR0
0 0 0 0 0 0 0 0
Description
EDSS DSS
0 0b0000
0 0b0001
0 0b0010
0 0b0011
0 0b0100
0 0b0101
0 0b0110
0 0b0111
0 0b1000
0 0b1001
0 0b1010
0 0b1011
0 0b1100
0 0b1101
0 0b1110
0 0b1111
Intel® PXA255 Processor Developer's Manual
Network SSP Serial Port
11 10 9 8 7 6 5 4
0 0 0 0 0 ? 0 0
Data Size
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
3 2 1 0
0 0 0 0