Network SSP Serial Port

Table 16-3. SSCR0 Bit Definitions (Sheet 2 of 2)

 

 

 

0x4140_0000

 

 

 

 

 

 

SSCR0

 

 

 

 

 

Network SSP Serial Port

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

 

EDSS

 

 

 

 

 

SCR

 

 

 

 

 

SSE

reserved

FRF

 

 

DSS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

? ? ? ? ? ? ? ? ? ? ? 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ? 0 0 0 0 0 0

Bits

Name

 

 

 

Description

 

 

 

 

 

 

 

 

 

 

 

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

EDSS

DSS

Data Size

 

 

 

1

0b0000

17-bit data

0

0b0000

reserved, undefined

 

 

 

1

0b0001

18-bit data

0

0b0001

reserved, undefined

3:0

DSS

1

0b0010

19-bit data

0

0b0010

reserved, undefined

1

0b0011

20-bit data

0

0b0011

4-bit data

 

 

 

 

 

 

1

0b0100

21-bit data

0

0b0100

5-bit data

 

 

 

1

0b0101

22-bit data

0

0b0101

6-bit data

 

 

 

1

0b0110

23-bit data

0

0b0110

7-bit data

 

 

 

1

0b0111

24-bit data

0

0b0111

8-bit data

 

 

 

1

0b1000

25-bit data

0

0b1000

9-bit data

 

 

 

1

0b1001

26-bit data

0

0b1001

10-bit data

 

 

 

1

0b1010

27-bit data

0

0b1010

11-bit data

 

 

 

1

0b1011

28-bit data

0

0b1011

12-bit data

 

 

 

1

0b1100

29-bit data

0

0b1100

13-bit data

 

 

 

1

0b1101

30-bit data

0

0b1101

14-bit data

 

 

 

1

0b1110

31-bit data

0

0b1110

15-bit data

 

 

 

1

0b1111

32-bit data

0

0b1111

16-bit data

 

 

 

 

 

 

 

 

 

16.5.2SSP Control Register 1 (SSCR1)

SSCR1, shown in Table 16-4,contains bit fields that control various SSP functions. Before 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

Intel® PXA255 Processor Developer’s Manual

Page 562
Image 562
Intel PXA255 manual SSCR0 Bit Definitions Sheet 2, Edss SCR SSE, Data Size Select, Edss DSS