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Synchronous Serial Interface (SSI)
24-38
Freescale Semiconductor
sections with internal or external clock and in normal mode. Gated clocks are not allowed in network
mode. Refer to
for SSI configuration for gated mode operation.
The clock operates when the TE bit and/or the RE bit are appropriately enabled. For an internally generated
clock, all internal bit clocks, word clocks, and frame clocks continue to operate. When a valid time slot
occurs (such as the first time slot in normal mode), the internal bit clock is enabled onto the clock port.
This allows data to be transferred out in periodic intervals in gated clock mode. With an external clock, the
SSI module waits for a clock signal to be received. After the clock begins, valid data is shifted in. Care
should be taken to clear all DC bits when the module is used in gated mode.
For gated clock operated in external clock mode, proper clock signalling must apply to SSI_BCLK for it
to function properly. If the SSI uses rising edge transition to clock data (TSCKP = 0) and falling edge
transition to latch data (RSCKP = 0), the clock must be in an active low state when idle. If the SSI uses
falling edge transition to clock data (TSCKP = 1) and rising edge transition to latch data (RSCKP = 1), the
clock must be in a active high state when idle. The following diagrams illustrate the different edge
clocking/latching.
Figure 24-31. Internal Gated Mode Timing - Rising Edge Clocking/Falling Edge Latching
Figure 24-32. Internal Gated Mode Timing - Falling Edge Clocking/Rising Edge Latching
Figure 24-33. External Gated Mode Timing - Rising Edge Clocking/Falling Edge Latching
TSCKP=0, RSCKP=0
SSI_BCLK
SSI_TXD
SSI_RXD
TSCKP=1, RSCKP=1
SSI_BCLK
SSI_TXD
SSI_RXD
TSCKP=0, RSCKP=0
SSI_BCLK
SSI_TXD
SSI_RXD
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...