![NEC V854 UPD703006 User Manual Download Page 176](http://html.mh-extra.com/html/nec/v854-upd703006/v854-upd703006_user-manual_249287176.webp)
176
User’s Manual U11969EJ3V0UM00
CHAPTER 7 TIMER/COUNTER FUNCTION (REAL-TIME PULSE UNIT)
7.4.3 Overflow
If the TM0 register overflows as a result of counting the count clock frequency to FFFFFFH, a flag is set to the
OVF0 flag of the TOVS registers, and an overflow interrupt (INTOV0) is generated. The value of the OVF0 flag is
retained until it is changed by user application.
The operation of the TM0 register after occurrence of overflow is determined by the OST0 bit.
(1) Operation after occurrence of overflow when OST0 = 0
The TM0 register continues counting.
(2) Operation after occurrence of overflow when OST0 = 1
TM0 = 000000H is retained, and the TM0 register stops counting. At this time TM0 stops with CE0 = 1. Perform
the following to resume counting.
• When ECLR0 = 0 : write 1 to CE0 bit
• When ECLR0 = 1 : trigger input to timer clear pin (TCLR0)
The operation is not affected even if the CE0 bit is set to 1 during count operation.
Figure 7-2. Operation after Occurrence of Overflow (when ECLR0 = 0, OST0 = 1)
Remark ECLR0 = 0
TM0
INTOV0
0
OST0
←
1
CE0
←
1
CE0
←
1
Count starts
Overflow
FFFFFFH
Overflow
FFFFFFH
Summary of Contents for V854 UPD703006
Page 2: ...2 User s Manual U11969EJ3V0UM00 MEMO ...
Page 22: ...22 User s Manual U11969EJ3V0UM00 MEMO ...
Page 80: ...80 User s Manual U11969EJ3V0UM00 MEMO ...
Page 134: ...134 User s Manual U11969EJ3V0UM00 MEMO ...
Page 156: ...156 User s Manual U11969EJ3V0UM00 MEMO ...
Page 294: ...294 User s Manual U11969EJ3V0UM00 MEMO ...
Page 320: ...320 User s Manual U11969EJ3V0UM00 MEMO ...
Page 324: ...324 User s Manual U11969EJ3V0UM00 MEMO ...
Page 336: ...336 User s Manual U11969EJ3V0UM00 MEMO ...
Page 376: ...376 User s Manual U11969EJ3V0UM00 MEMO ...
Page 382: ...382 User s Manual U11969EJ3V0UM00 MEMO ...
Page 394: ...394 User s Manual U11969EJ3V0UM00 MEMO ...