NEC mPD780852 Series, Preliminary User'S Manual

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CHAPTER 11 CLOCK OUTPUT CONTROLLER
Preliminary User’s Manual U14581EJ3V0UM00
11.4 Clock Output Controller Operation
To output the clock pulse, follow the procedure described below.
<1> Select the clock pulse output frequency with bits 0 to 2 (CCS0 to CCS2) of the clock output selection register
(CKS) (clock pulse output in disabled status).
<2> Set bit 0 (TPOE) of the 16-bit timer mode control register (TMC0) to 0 (prescaler signal 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.
Caution The clock output cannot be used if the output latch of P60 is set to 1.
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 11-4, 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 11-4. Remote Control Output Application Example
CLOE
Clock output
* *