NEC 78K0 User Manual page 198

If the setting value of the CMP01 register is N, the setting value of the CMP11 register is M, and the count clock
frequency is f , the carrier clock output cycle and duty are as follows.
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Carrier clock output cycle = (N + M + 2)/f
Duty = High-level width : Carrier clock output width = ( M + 1) : (N + M + 2)
Cautions 1. Be sure to set the CMP11 register when starting the timer count operation (TMHE1 = 1) after
the timer count operation was stopped (TMHE1 = 0) (be sure to set again even if setting the
same value to the CMP11 register).
2. Set so that the count clock frequency of TMH1 becomes more than 6 times the count clock
frequency of TM51.
(4) Timing chart
The carrier output control timing is shown below.
Cautions 1. Set the values of the CMP01 and CMP11 registers in a range of 01H to FFH.
2. In the carrier generator mode, three operating clocks (signal selected by CKS12 to CKS10
bits of TMHMD1 register) or more are required from when the CMP11 register value is
changed to when the value is transferred to the register.
3. Be sure to set the RMC1 bit before the count operation is started.
198
CHAPTER 8 8-BIT TIMERS H0 AND H1
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User's Manual U16227EJ2V0UD