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CHAPTER 8 8-BIT TIMERS H0 AND H1
User’s Manual U19780EJ2V0UD
283
Figure 8-15. Carrier Generator Mode Operation Timing (2/3)
(b) Operation when CMP01 = N, CMP11 = M
N
CMP01
CMP11
TMHE1
INTTMH1
Carrier clock
TM51 count value
00H
N
00H 01H
M
00H
N
00H 01H
M
00H
00H
N
M
TCE51
TOH1
0
0
1
1
0
0
1
1
0
0
INTTM51
NRZB1
NRZ1
Carrier clock
00H 01H
K
00H 01H
L
00H 01H
M 00H 01H
00H 01H
N
INTTM5H1
<1><2>
<3>
<4>
<5>
<6>
<7>
8-bit timer 51
count clock
8-bit timer H1
count clock
8-bit timer counter
H1 count value
K
CR51
L
M
N
<1> When TMHE1 = 0 and TCE51 = 0, the 8-bit timer counter H1 operation is stopped.
<2> When TMHE1 = 1 is set, the 8-bit timer counter H1 starts a count operation. At that time, the carrier clock
remains default.
<3> When the count value of the 8-bit timer counter H1 matches the CMP01 register value, the first INTTMH1
signal is generated, the carrier clock signal is inverted, and the compare register to be compared with the 8-
bit timer counter H1 is switched from the CMP01 register to the CMP11 register. The 8-bit timer counter H1
is cleared to 00H.
<4> When the count value of the 8-bit timer counter H1 matches the CMP11 register value, the INTTMH1 signal
is generated, the carrier clock signal is inverted, and the compare register to be compared with the 8-bit timer
counter H1 is switched from the CMP11 register to the CMP01 register. The 8-bit timer counter H1 is cleared
to 00H. By performing procedures <3> and <4> repeatedly, a carrier clock with duty fixed to other than 50%
is generated.
<5> When the INTTM51 signal is generated, it is synchronized with the 8-bit timer H1 count clock and is output as
the INTTM5H1 signal.
<6> A carrier signal is output at the first rising edge of the carrier clock if NRZ1 is set to 1.
<7> When NRZ1 = 0, the TOH1 output is held at the high level and is not changed to low level while the carrier
clock is high level (from <6> and <7>, the high-level width of the carrier clock waveform is guaranteed).
Remark
INTTM5H1 is an internal signal and not an interrupt source.