
Synchronous Serial Interface (SSI)
24-44
Freescale Semiconductor
(PSR), prescaler modulus (PM), and frame rate (DC) selects the ratio of SSI_MCLK to sampling clock,
SSI_FS. In I
2
S mode, the oversampling clock is available on this port if the SSI_CR[MCE] bit is set.
shows the relationship between the clocks and the dividers. The bit clock can be received
from an SSI clock port or generated from the internal clock (SSI_CLOCK) through a divider, as shown in
.
Figure 24-36. SSI Clocking
24.4.2.1
SSI Clock and Frame Sync Generation
Data clock and frame sync signals can be generated internally or obtained from external sources. If
internally generated, the SSI clock generator derives bit clock and frame sync signals from the
SSI_CLOCK. The SSI clock generator consists of a selectable, fixed prescaler and a programmable
prescaler for bit rate clock generation. A programmable frame rate divider and a word length divider are
used for frame rate sync signal generation.
shows a block diagram of the clock generator for the transmit section. The serial bit clock
can be internal or external, depending on the transmit direction (SSI_TCR[TXDIR]) bit.
Figure 24-37. SSI Transmit Clock Generator Block Diagram
shows the frame sync generator block for the transmit section. When internally generated,
receive and transmit frame sync generate from the word clock and are defined by the frame rate divider
(DC) bits and the word length (WL) bits of the SSI_CCR.
Serial Bit Clock
Word Divider
(/8, /10, /12, /16,
Word clock
Frame Divider
(/1 to /32)
Frame clock
/18, /20, /22, /24)
Prescaler
(/1 or /8)
Divider
(/1 to /256)
TXDIR(1=output)
TXDIR(0=input)
Serial Bit Clock
TXDIR(1=output)
Word Length
Divider
Word clock
SSI_CCR[WL]
SSI_CCR[PSR]
SSI_CCR[PM]
TXDIR
MCE
Divider
(/1 or /2)
SSI_CCR[DIV2]
Divide by
2
SSI_CLKIN
Internal core clock
(f
sys
)
MISCCR[SSISRC]
1
0
CDR[SSIDIV]
Divider
(/3 to /62)
CCM
SSI_CLOCK
SSI_BCLK
SSI_MCLK
MCF5329 Reference Manual, Rev 3
Содержание MCF5329
Страница 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 126: ...Enhanced Multiply Accumulate Unit EMAC 4 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 564: ...Liquid Crystal Display Controller LCDC 22 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 692: ...Programmable Interrupt Timers PIT0 PIT3 28 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 720: ...Queued Serial Peripheral Interface QSPI 30 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 790: ...Message Digest Hardware Accelerator MDHA 33 20 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Страница 902: ...Register Memory Map Quick Reference A 26 Freescale Semiconductor MCF5329 Reference Manual Rev 3...