SIC63616-(Rev. 1.0) NO. P106
3240-0412
4.9.9 Clock output to serial interface and R/f converter
The signal that is made from underflows of Timer 1 by dividing them by 2, can be used as the clock source
for the serial interface and R/f converter.
Timer 1 always outputs the clock to the serial interface and R/f converter by setting Timer 1 into RUN state
(PTRUN1 = "1"). It is not necessary to control with the PTOUT_A register.
PTRUN1
Timer 1 underflow
Source clock for serial I/F
and R/f converter
Fig. 4.9.9.1 Clock output to serial interface and R/f converter
A setting value for the RLD1x register according to a transfer rate of the serial interface is calculated by the
following expression:
f
CNT1
RLD1x = ————— - 1
2
∗
bps
f
CNT1
: Timer 1 count clock frequency set by the PTPS1 register (See Table 4.9.2.1.)
bps
: Transfer rate
(00H can be set to RLD1x)
Be aware that the maximum clock frequency for the serial interface is limited to 1 MHz when OSC3 is used
as the clock source.