NEC mPD78F0730, Preliminary User'S Manual

Page: 214 / 518

CHAPTER 8 8-BIT TIMER H1
Preliminary User’s Manual U19014EJ1V0UD
214
Figure 8-13. Carrier Generator Mode Operation Timing (1/3)
(a) Operation when CMP01 = N, CMP11 = N
CMP01
CMP11
TMHE11
INTTMH1
Carrier clock
00H N 00H N 00H N 00H N 00H N 00H N
N
N
8-bit timer 51
count clock
TM51 count value
CR51
TCE51
TOH11
0
0
1
1
0
0
1
1
0
0
INTTM5n1
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 H1
count clock
8-bit timer counter
H1 count value
K 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, 8-bit timer counter H1 starts a count operation. At that time, the carrier clock
remains default.
<3> When the count value of 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 8-bit timer
counter H1 is switched from the CMP01 register to the CMP11 register. 8-bit timer counter H1 is cleared to
00H.
<4> When the count value of 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 8-bit timer
counter H1 is switched from the CMP11 register to the CMP01 register. 8-bit timer counter H1 is cleared to
00H. By performing procedures <3> and <4> repeatedly, a carrier clock with duty fixed to 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> The INTTM5H1 signal becomes the data transfer signal for the NRZB1 bit, and the NRZB1 bit value is
transferred to the NRZ1 bit.
<7> When NRZ1 = 0 is set, the TOH1 output becomes low level.
Downloaded from Elcodis.com electronic components distributor