Operations Of Clock Output/Buzzer Output Controller; Operation As Clock Output; Operation As Buzzer Output - NEC mPD780024AS Series Preliminary User's Manual

CHAPTER 10 CLOCK OUTPUT/BUZZER OUTPUT CONTROLLER

10.4 Operations of Clock Output/Buzzer Output Controller

10.4.1 Operation as clock output

The clock pulse is output as the following procedure.
<1> Select the clock pulse output frequency with bits 0 to 3 (CCS0 to CCS3) of the clock output select register
(CKS) (clock pulse output in disabled status).
<2> Set bit 4 (CLOE) of CKS to 1 to enable clock output.
Remark The clock output controller is designed not to output pulses with a small width during output enable/
disable switching of the clock output. As shown in Figure 10-4, be sure to start output from the low period
of the clock (marked with * in the figure). When stopping output, do so after securing high level of the
clock.
Figure 10-4. Remote Control Output Application Example
CLOE
Clock output

10.4.2 Operation as buzzer output

The buzzer frequency is output as the following procedure.
<1> Select the buzzer output frequency with bits 5 and 6 (BCS0, BCS1) of the clock output select register (CKS)
(buzzer output in disabled status).
<2> Set bit 7 (BZOE) of CKS to 1 to enable buzzer output.
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