NEC PD754144 User Manual
Page 179
CHAPTER 6 PERIPHERAL HARDWARE FUNCTION
179
User’s Manual U10676EJ3V0UM
(7) Notes on application of carrier generator (restarting)
If forced reloading is performed by directly rewriting the contents of the no return zero flag (NRZ) and then
the timer is restarted (by setting bit 3 of TM2 to “1”) when the carrier clock is high (TOUT F/F holds “1”), the
carrier may not be output to the PTO2 pin as shown below.
1
0
0
1
PTO2
TOUT F/F
NRZ
SET1 NRZ
SET1 TM2.3
Carrier is
not output
0
1
1
1
Clock
0
0
Likewise, if forced reloading is performed by directly rewriting the contents of NRZ and the timer is restarted
(by setting bit 3 of TM2 to “1”) when the carrier clock is high (TOUT F/F holds “1”), the high-level period of
the carrier output to the PTO2 pin may be extended as shown below.
1
0
0
1
PTO2
TOUT F/F
NRZ
CLR1 NRZ
SET1 TM2.3
High-level period of
carrier is extended
0
1
1
1
Clock
0
0