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Synchronous Serial Interface (SSI)
Freescale Semiconductor
24-47
The supported data formats are:
•
msb alignment
•
lsb alignment
— Zero-extended (receive data only)
— Sign-extended (receive data only)
With msb alignment, the most significant byte is bits 31–24 of the data register if the word length is larger
than, or equal to, 16 bits. If the word length is less than 16 bits and msb alignment is chosen, the most
significant byte is bits 15–8. With lsb alignment, the least significant byte is bits 7–0. The
SSI_TCR[TXBIT0] and the SSI_RCR[RXBIT0] bits control data alignment.
shows the bit
assignment for all the data formats supported by the SSI module.
In addition, if lsb alignment is selected, the receive data can be zero-extended or sign-extended.
•
In zero-extension, all bits above the most significant bit are 0s. This format is useful when data is
stored in a pure integer format.
•
In sign-extension, all bits above the most significant bit are equal to the most significant bit. This
format is useful when data is stored in a fixed-point integer format (which implies fractional
values).
Table 24-24. Data Alignment
Format
Bit Number
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
8-bit lsb Aligned
7
6
5
4
3
2
1
0
8-bit msb Aligned
7
6
5
4
3
2
1
0
10-bit lsb Aligned
9
8
7
6
5
4
3
2
1
0
10-bit msb Aligned
9
8
7
6
5
4
3
2
1
0
12-bit lsb Aligned
11 10
9
8
7
6
5
4
3
2
1
0
12-bit msb Aligned
11 10
9
8
7
6
5
4
3
2
1
0
16-bit lsb Aligned
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
16-bit msb Aligned
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
18-bit lsb Aligned
17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
18-bit msb Aligned
17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
20-bit lsb Aligned
19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
20-bit msb Aligned
19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
22-bit lsb Aligned
21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
22-bit msb Aligned
21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
24-bit lsb Aligned
23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
24-bit msb Aligned
23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...