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CHAPTER 12 CLOCK OUTPUT CONTROL CIRCUIT
12.4 Clock Output Control Circuit Operation
12.4.1 Clock output operation
To output the clock pulse, follow the procedure described below.
<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 3 (SGOB) of the sound generator control register (SGCR) to 1 (SGOF output in disabled status).
<3>
Set the P60 output latch to 0.
<4>
Set bit 0 (PM60) of port mode register 6 to 0 (set to output mode).
<5>
Set bit 4 (CLOE) of CKS to 1, and enable clock output.
Remark
The clock output control circuit 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 below). When stopping output, do so after securing high level
of the clock.
Figure 12-4. Remote Control Output Application Example
CLOE
Clock output
*
*
Содержание mPD780973 Series
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