489
32072H–AVR32–10/2012
AT32UC3A3
23.8.10
Identifying Bus Events
This chapter lists the different bus events, and how they affect bits in the TWIM registers. This is
intended to help writing drivers for the TWIM.
Table 23-5.
Bus Events
Event
Effect
Master transmitter has sent
a data byte
SR.THR is cleared.
Master receiver has
received a data byte
SR.RHR is set.
Start+Sadr sent, no ack
received from slave
SR.ANAK is set.
SR.CCOMP not set.
CMDR.VALID remains set.
STOP automatically transmitted on bus.
Data byte sent to slave, no
ack received from slave
SR.DNAK is set.
SR.CCOMP not set.
CMDR.VALID remains set.
STOP automatically transmitted on bus.
Arbitration lost
SR.ARBLST is set.
SR.CCOMP not set.
CMDR.VALID remains set.
TWCK and TWD immediately released to a pulled-up state.
SMBus Alert received
SR.SMBALERT is set.
SMBus timeout received
SR.SMBTOUT is set.
SR.CCOMP not set.
CMDR.VALID remains set.
STOP automatically transmitted on bus.
Master transmitter receives
SMBus PEC Error
SR.DNAK is set.
SR.CCOMP not set.
CMDR.VALID remains set.
STOP automatically transmitted on bus.
Master receiver discovers
SMBus PEC Error
SR.PECERR is set.
SR.CCOMP not set.
CMDR.VALID remains set.
STOP automatically transmitted on bus.
CR.STOP is written by user
SR.STOP is set.
SR.CCOMP set.
CMDR.VALID remains set.
STOP transmitted on bus after current byte transfer has finished.
Summary of Contents for AT32UC3A3128
Page 61: ...61 32072H AVR32 10 2012 AT32UC3A3 PLLEN PLL Enable 0 PLL is disabled 1 PLL is enabled...
Page 592: ...592 32072H AVR32 10 2012 AT32UC3A3 Manchester Configuration Register on page 614...
Page 989: ...989 32072H AVR32 10 2012 AT32UC3A3 37 2 Package Drawings Figure 37 1 TFBGA 144 package drawing...
Page 991: ...991 32072H AVR32 10 2012 AT32UC3A3 Figure 37 3 VFBGA 100 package drawing...