Watch Timer Mode Control Register Format - NEC PD78056F User Manual

(2) Watch timer mode control register (TMC2)
This register sets the watch timer operating mode, watch flag set time and prescaler interval time and enables/
disables prescaler and 5-bit counter operations.
TMC2 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets TMC2 to 00H.
Figure 10-3. Watch Timer Mode Control Register Format
7 6 5
Symbol
0 TMC26 TMC25 TMC24
TMC2
TMC20
0 Normal operating mode (flag set at f
1 Fast feed operating mode (flag set at f
TMC21
0 Clear after operation stop
1 Operation enable
TMC22
0 Clear after operation stop
1 Operation enable
TMC23
f = 5.0 MHz Operation
XX
14
0 2 /f (0.4 sec)
W
13
1 2 /f (0.2 sec)
W
TMC26 TMC25 TMC24
0 0 0 2
0 1
0 2
0 1 0 2
0 1 1 2
1 0 0 2
1 0 1 2
Other than above Setting prohibited
Caution When the watch timer is used, the prescaler should not be cleared frequently.
Remarks f
W
f
XX
f
X
f
XT
CHAPTER 10 WATCH TIMER
4 3 2 1 0
TMC23 TMC22 TMC21 TMC20
Watch Operating Mode Selection
14
/2 )
W
5
/2 )
W
Prescaler Operation Control
5-Bit Counter Operation Control
Watch Flag Set Time Selection
f = 4.19 MHz Operation
XX
14
2 /f (0.5 sec)
W
13
2 /f (0.25 sec)
W
Prescaler Interval Time Selection
f = 5.0 MHz Operation
XX
4
/f (410 s) 2
W
5
/f (819 s) 2
W
6
/f (1.64 ms) 2
W
7
/f (3.28 ms) 2
W
8
/f (6.55 ms) 2
W
9
/f (13.1 ms) 2
W
: Watch timer clock frequency (f
: Main system clock frequency (f
: Main system clock oscillation frequency
: Subsystem clock oscillation frequency
After
Address
Reset
FF4AH 00H
f
XT
14
2 /f
W
13
2 /f
W
f = 4.19 MHz Operation
XX
4
/f (488 s) 2
W
5
/f (977 s) 2
W
6
/f (1.95 ms) 2
W
7
/f (3.91 ms) 2
W
8
/f (7.81 ms) 2
W
9
/f (15.6 ms) 2
W
7
/2 or f )
XX XT
or f /2)
X X
R/W
R/W
= 32.768 kHz Operation
(0.5 sec)
(0.25 sec)
f = 32.768 kHz Operation
XT
4
/f (488 s)
W
5
/f (977 s)
W
6
/f (1.95 ms)
W
7
/f (3.91 ms)
W
8
/f (7.81 ms)
W
9
/f (15.6 ms)
W
243