NEC 78K0 User Manual page 201

Figure 8-15. Carrier Generator Mode Operation Timing (3/3)
8-bit timer H1
count clock
8-bit timer counter
00H 01H
H1 count value
CMP01
CMP11
TMHE1
INTTMH1
Carrier clock
<1>
<1> When TMHE1 = 1 is set, 8-bit timer counter H1 starts a count operation. At that time, the carrier clock is held
at the inactive level.
<2> When the count value of 8-bit timer counter H1 matches the CMP01 register value, 8-bit timer counter H1 is
cleared and the INTTMH1 signal is output.
<3> The CMP11 register can be rewritten during 8-bit timer H1 operation, however, the changed value (L) is
latched. The CMP11 register is changed when the count value of 8-bit timer counter H1 and the CMP11
register value before the change (M) match (<3>').
<4> When the count value of 8-bit timer counter H1 and the CMP11 register value before the change (M) match,
the INTTMH1 signal is output, the carrier signal is inverted, and 8-bit timer counter H1 is cleared to 00H.
<5> The timing at which the count value of 8-bit timer counter H1 and the CMP11 register value match again is
indicated by the value after the change (L).
CHAPTER 8 8-BIT TIMERS H0 AND H1
(c) Operation when CMP11 is changed
N 00H 01H
<3>
M
M (L)
<2>
User's Manual U16227EJ2V0UD
00H N 00H 01H
M
N
<3>'
L
<4>
L 00H
<5>
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