
Synchronous Serial Interface (SSI)
24-32
Freescale Semiconductor
With the above conditions in normal mode with a continuous clock, each time the frame sync signal is
generated (or detected), a data word is clocked in. With the above conditions and a gated clock, each time
the clock begins, a data word is clocked in.
If receive FIFO 0 is not enabled, the received data word is transferred from the receive shift register
(RXSR) to the receive data register 0 (SSI_RX0), and the RDR0 flag is set. Receive interrupt 0 occurs if
the RIE and SSI_IER[RDR0] bits are set.
If receive FIFO 0 is enabled, the received data word is transferred to the receive FIFO 0. The RFF0 flag is
set if the receive data register (SSI_RX0) is full and receive FIFO 0 reaches the selected threshold. Receive
interrupt 0 occurs if RIE and SSI_IER[RFF0] bits are set.
The core has to read the data from the SSI_RX0 register before a new data word is transferred from the
RXSR; otherwise, receive overrun error 0 (ROE0) bit is set. If receive FIFO 0 is enabled, the ROE0 bit is
set when the receive FIFO 0 data level reaches the selected threshold and a new data word is ready to
transfer to the receive FIFO 0.
shows transmitter and receiver timing for an 8-bit word with two words per time slot in
normal mode and continuous clock with a late word length frame sync. The Tx data register is loaded with
the data to be transmitted. On arrival of the frame sync, this data is transferred to the transmit shift register
and transmitted on the SSI_TXD output. Simultaneously, the receive shift register shifts in the received
data available on the SSI_RXD input. At the end of the time slot, this data is transferred to the Rx data
register.
Figure 24-27. Normal Mode Timing - Continuous Clock
shows a similar case for internal (SSI generates clock) gated clock mode, and
shows a case for external (SSI receives clock) gated clock mode.
NOTE
A pull-down resistor is required in gated clock mode, because the clock port
is disabled between transmissions.
The Tx data register is loaded with the data to be transmitted. On arrival of the clock, this data transfers to
the transmit shift register and transmits on the SSI_TXD output. Simultaneously, the receive shift register
shifts in the received data available on the SSI_RXD input, and at the end of the time slot, this data
transfers to the Rx data register. In internal gated clock mode, the Tx data line and clock output port are
Tx Data
Rx Data
Continuous
SSI_TXD
SSI_RXD
SSI_BCLK
SSI_FS
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...