210
CHAPTER 11 WATCH TIMER
11.1 Overview of Watch Timer
The watch timer is a 15-bit timer using the sub-clock. This timer can generate interval
interrupts. Furthermore, depending on the setting, this timer can be used as the clock
source for the watchdog timer.
■
Functions of watch timer
The watch timer is composed of a 15-bit timer and a circuit to control interval interrupts.
The watch timer uses the sub-clock regardless of the PLL clock selection bit (MCS) or the sub-
clock selection bit (SCS) in the clock selection register (CKSCR).
Table 11.1-1 lists the interval times of the watch timer.
Table 11.1-1 Interval times of watch timer
WTC2
WTC1
WTC0
Interval time
*
0
0
0
31.25 ms
0
0
1
62.5 ms
0
1
0
125 ms
0
1
1
250 ms
1
0
0
500 ms
1
0
1
1.000 s
1
1
0
2.000 s
1
1
1
Setting is prohibited
*: Sub-clock: 32 kHz frequency divided by 4 (= 8 kHz)
Summary of Contents for MB90480 Series
Page 2: ......
Page 4: ......
Page 10: ...vi ...
Page 128: ...106 CHAPTER 4 RESET ...
Page 174: ...152 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Page 198: ...176 CHAPTER 7 MODE SETTING ...
Page 220: ...198 CHAPTER 9 TIMEBASE TIMER ...
Page 238: ...216 CHAPTER 11 WATCH TIMER ...
Page 280: ...258 CHAPTER 12 16 BIT INPUT OUTPUT TIMER ...
Page 406: ...384 CHAPTER 17 8 10 BIT A D CONVERTER ...
Page 478: ...456 CHAPTER 20 CHIP SELECTION FACILITY ...
Page 494: ...472 CHAPTER 21 ADDRESS MATCH DETECTION FUNCTION ...
Page 498: ...476 CHAPTER 22 ROM MIRROR FUNCTION SELECTION MODULE ...
Page 526: ...504 CHAPTER 23 2M 3M BIT FLASH MEMORY ...
Page 536: ...514 CHAPTER 24 EXAMPLES OF MB90F481B MB90F482B MB90F488B MB90F489B SERIAL PROGRAMMING ...
Page 570: ...548 CHAPTER 25 PWC TIMER ONLY MB90485 SERIES ...
Page 688: ......