Clock Output/Buzzer Output Controller Operations; Clock Output Operation; Operation As Buzzer Output; Remote Control Output Application Example - NEC 78K0 User Manual

12.4 Clock Output/Buzzer Output Controller Operations

12.4.1 Clock output operation

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 selection 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 12-4, 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.
CLOE
Clock output

12.4.2 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 selection register
(CKS) (buzzer output in disabled status).
<2> Set bit 7 (BZOE) of CKS to 1 to enable buzzer output.
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CHAPTER 12 CLOCK OUTPUT/BUZZER OUTPUT CONTROLLER
Figure 12-4. Remote Control Output Application Example
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