34.7.5.9 Synchronization Busy

Table 34-34. Register Bit Attribute Legend
SymbolDescriptionSymbolDescriptionSymbolDescription
RReadable bitHCCleared by Hardware(Grey cell)Unimplemented
WWritable bitHSSet by HardwareXBit is unknown at Reset
KWrite to clearSSoftware settable bit
Name: SYNCBUSY
Offset: 0x1C
Reset: 0x00000000
Property: -

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
          
Access  
Reset  
Bit 15141312111098 
          
Access  
Reset  
Bit 76543210 
    LENGTH CTRLBENABLESWRST 
Access RRRR 
Reset 0000 

Bit 4 – LENGTH LENGTH Synchronization Busy

Writing to the LENGTH register requires synchronization. When writing to LENGTH, SYNCBUSY.LENGTH will be asserted until synchronization is complete. If the LENGTH register is written to while SYNCBUSY.LENGTH is asserted, a bus error is generated.

Note: In client mode, the clock is only running during data transfer, so SYNCBUSY.LENGTH will remain asserted until the next data transfer begins.
ValueDescription
0LENGTH synchronization is not busy.
1LENGTH synchronization is busy.

Bit 2 – CTRLB CTRLB Synchronization Busy

Writing to the CTRLB when the SERCOM is enabled requires synchronization. Ongoing synchronization is indicated by SYNCBUSY.CTRLB=1 until synchronization is complete, after which the bit will read zero. If CTRLB is written while SYNCBUSY.CTRLB=1, a bus error will be generated.

ValueDescription
0CTRLB synchronization is not busy.
1CTRLB synchronization is busy.

Bit 1 – ENABLE SERCOM Enable Synchronization Busy

Enabling and disabling the SERCOM (CTRLA.ENABLE) requires synchronization. Ongoing synchronization is indicated by SYNCBUSY.ENABLE=1 until synchronization is complete, after which it will read zero.

ValueDescription
0Enable synchronization is not busy.
1Enable synchronization is busy.

Bit 0 – SWRST Software Reset Synchronization Busy

Resetting the SERCOM (CTRLA.SWRST) requires synchronization. Ongoing synchronization is indicated by SYNCBUSY.SWRST=1 until synchronization is complete, after which it will read zero.

ValueDescription
0SWRST synchronization is not busy.
1SWRST synchronization is busy.