30-42
MC9328MX1 Reference Manual
MOTOROLA
Synchronous Serial Interface (SSI)
Clearing the TE bit disables the transmitter (and the SSI_TXDAT pin) after transmission of the current
data word is complete. Setting the TE bit enables transmission of the next word. The TE bit is cleared after
the TDE bit is set to ensure that all pending data is transmitted.
To summarize, in network mode, the transmitter can generate an interrupt during every enabled time slot or
require the DSP program to poll the TDE bit. When the TDE bit is set, the MC9328MX1 responds with
one of the following actions:
•
Write data to the STX register—enables transmission in the next time slot.
•
Write to the SSI Time Slot Register (STSR)—disables transmission in the next time slot.
•
Do nothing—causes a transmit underrun to occur at the beginning of the next time slot (the previous
data is re-transmitted).
30.5.2.2 Network Mode Receive
The receiver portion of the SSI is enabled when both the SSI_EN and the RE bits in the SCSR are set.
However, the receive enable takes place during that time slot only if the RE bit is enabled before the
second to last bit of the word. When the RE bit is cleared, the receiver is disabled immediately. SSI is
capable of finding the start of the next frame automatically. The word is received into the RXSR and then
transferred to the SRX register when the whole word is received. The transfer to the SRX register sets the
RDR bit. When the RIE bit is set, setting the RDR bit causes a receive interrupt to occur.
After the received word is transferred to the SRX register, the second data word (second time slot in the
frame), begins shifting in immediately. The DSP program must read the data from the SRX register (this
clears the RDR bit) before the second data word is completely received into the RXSR or a receive overrun
error occurs. This is detected by the ROE bit of the SCSR.
To summarize, in network mode, the receiver can generate an interrupt during every enabled time slot or
require the DSP program to poll the RDR bit. When the TDE bit is set, the MC9328MX1 responds with
one of the following actions:
•
Read the SRX register and use the data.
•
Read the SRX register and ignore the data.
•
Do nothing—a receiver overrun occurs at the end of the current time slot.
NOTE:
For a continuous clock, the optional frame sync output and clock output
signals are not affected even when the transmitter or receiver is disabled.
The TE and RE bits do not disable the bit clock or the frame sync
generation. The only way to disable the bit clock and the frame sync
generation is to disable the SSI_EN bit in the SCSR.
Figure 30-19 on page 30-43 shows the transmitter and receiver timing for an 8-bit word with continuous
clock, with the FIFO disabled, and with a frame size of three words per frame sync, operating in network
mode.
Содержание DragonBall MC9328MX1
Страница 68: ...1 12 MC9328MX1 Reference Manual MOTOROLA Introduction ...
Страница 86: ...2 18 MC9328MX1 Reference Manual MOTOROLA Signal Descriptions and Pin Assignments ...
Страница 116: ...3 30 MC9328MX1 Reference Manual MOTOROLA Memory Map ...
Страница 126: ...4 10 MC9328MX1 Reference Manual MOTOROLA ARM920T Processor ...
Страница 160: ...8 8 MC9328MX1 Reference Manual MOTOROLA System Control ...
Страница 272: ...13 32 MC9328MX1 Reference Manual MOTOROLA DMA Controller ...
Страница 281: ...Programming Model MOTOROLA Watchdog Timer Module 14 9 ...
Страница 282: ...14 10 MC9328MX1 Reference Manual MOTOROLA Watchdog Timer Module ...
Страница 300: ...15 18 MC9328MX1 Reference Manual MOTOROLA Analog Signal Processor ASP ...
Страница 438: ...18 16 MC9328MX1 Reference Manual MOTOROLA Serial Peripheral Interface Modules SPI 1 and SPI 2 ...
Страница 478: ...19 40 MC9328MX1 Reference Manual MOTOROLA LCD Controller ...
Страница 542: ...20 64 MC9328MX1 Reference Manual MOTOROLA Multimedia Card Secure Digital Host Controller Module MMC SD ...
Страница 574: ...21 32 MC9328MX1 Reference Manual MOTOROLA Memory Stick Host Controller MSHC Module ...
Страница 598: ...23 16 MC9328MX1 Reference Manual MOTOROLA Real Time Clock RTC ...
Страница 670: ...24 72 MC9328MX1 Reference Manual MOTOROLA SDRAM Memory Controller ...
Страница 726: ...25 56 MC9328MX1 Reference Manual MOTOROLA SmartCard Interface Module SIM ...
Страница 736: ...26 10 MC9328MX1 Reference Manual MOTOROLA General Purpose Timers ...
Страница 854: ...29 18 MC9328MX1 Reference Manual MOTOROLA I2C Module ...
Страница 900: ...30 46 MC9328MX1 Reference Manual MOTOROLA Synchronous Serial Interface SSI ...
Страница 942: ...32 26 MC9328MX1 Reference Manual MOTOROLA GPIO Module and I O Multiplexer IOMUX ...