
638
SAM9G45 [DATASHEET]
6438K–ATARM–12-Feb-13
34.7.1.2
Transmitter Clock Management
The transmitter clock is generated from the receiver clock or the divider clock or an external clock scanned on the
TK I/O pad. The transmitter clock is selected by the CKS field in SSC_TCMR (Transmit Clock Mode Register).
Transmit Clock can be inverted independently by the CKI bits in SSC_TCMR.
The transmitter can also drive the TK I/O pad continuously or be limited to the actual data transfer. The clock out-
put is configured by the SSC_TCMR register. The Transmit Clock Inversion (CKI) bits have no effect on the clock
outputs. Programming the TCMR register to select TK pin (CKS field) and at the same time Continuous Transmit
Clock (CKO field) might lead to unpredictable results.
Figure 34-7. Transmitter Clock Management
34.7.1.3
Receiver Clock Management
The receiver clock is generated from the transmitter clock or the divider clock or an external clock scanned on the
RK I/O pad. The Receive Clock is selected by the CKS field in SSC_RCMR (Receive Clock Mode Register).
Receive Clocks can be inverted independently by the CKI bits in SSC_RCMR.
The receiver can also drive the RK I/O pad continuously or be limited to the actual data transfer. The clock output
is configured by the SSC_RCMR register. The Receive Clock Inversion (CKI) bits have no effect on the clock out-
puts. Programming the RCMR register to select RK pin (CKS field) and at the same time Continuous Receive
Clock (CKO field) can lead to unpredictable results.
TK (pin)
Receiver
Clock
Divider
Clock
CKS
CKO
Data Transfer
CKI
CKG
Transmitter
Clock
Output
MUX
Tri_state
Controller
Tri-state
Controller
INV
MUX