(Tm1 And Tm2) Are Used As 16-Bit Timer/Event Counter; Square-Wave Output Operation Timing - NEC mPD780208 Subseries User Manual

(3) Square-wave output operation
Square-wave signals can be generated at the user-specified frequency. The frequency or pulse interval
is determined by the value preset in the 8-bit compare registers (CR10 and CR20). To set a count value,
set the value of the higher 8 bits to CR20, and the value of the lower 8 bits to CR10.
The TO2/P32 pin output status is reversed at intervals of the count value preset to CR10 and CR20 by
setting bit 4 (TOE2) of the 8-bit timer output control register (TOC1) to 1. This enables a square wave with
any selected frequency to be output.
Table 7-10. Square-Wave Output Ranges When 2-Channel 8-Bit Timer/Event Counters
TCL13 TCL12 TCL11
0 1 0
0 1 1
0 1 1
1 0 0
1 0 0
1 0 1
1 0 1
1 1 0
1 1 0
1 1 1
1 1 1
Remarks 1. f : Main system clock oscillation frequency
X
2. TCL10 to TCL13: Bits 0 to 3 of timer clock select register 1 (TCL1)
3. Figures in parentheses apply to operation with f
Count clock
TM1
00H
TM2
00H
CR10
CR20
TO2
Count start
CHAPTER 7 8-BIT TIMER/EVENT COUNTER

(TM1 and TM2) Are Used as 16-Bit Timer/Event Counter

TCL10 Minimum Pulse Width
1 2 x 1/f (400 ns)
X
2
0 2 x 1/f (800 ns)
X
(1.6 µ s)
1 2 3 x 1/f
X
(3.2 µ s)
4
0 2 x 1/f
X
(6.4 µ s)
5
1 2 x 1/f
X
(12.8 µ s)
0 2 6 x 1/f
X
(25.6 µ s)
7
1 2 x 1/f
X
(51.2 µ s)
0 2 8 x 1/f
X
(102.4 µ s)
9
1 2 x 1/f
X
(204.8 µ s)
0 2 10 x 1/f
X
(819.2 µ s)
1 2 12 x 1/f
X
Figure 7-13. Square-Wave Output Operation Timing
N N + 1 FFH 00H
01H
N
M
User's Manual U11302EJ4V0UM
Maximum Pulse Width
2 17 x 1/f (26.2 ms)
X
18
2 x 1/f (52.4 ms)
X
2 19 x 1/f (104.9 ms)
X
20
2 x 1/f (209.7 ms)
X
21
2 x 1/f (419.4 ms)
X
2 22 x 1/f (838.9 ms)
X
23
2 x 1/f (1.7 s)
X
2 24 x 1/f (3.4 s)
X
25
2 x 1/f (6.7 s)
X
2 26 x 1/f (13.4 s)
X
2 28 x 1/f (53.7 s)
X
= 5.0 MHz.
X
FFH 00H FFH 00H
01H 02H M – 1 M
Interval time
Resolution
2 x 1/f (400 ns)
X
2
2 x 1/f (800 ns)
X
(1.6 µ s)
2 3 x 1/f
X
(3.2 µ s)
4
2 x 1/f
X
(6.4 µ s)
5
2 x 1/f
X
(12.8 µ s)
2 6 x 1/f
X
(25.6 µ s)
7
2 x 1/f
X
(51.2 µ s)
2 8 x 1/f
X
(102.4 µ s)
9
2 x 1/f
X
(204.8 µ s)
2 10 x 1/f
X
(819.2 µ s)
2 12 x 1/f
X
01H N 00H 01H
00H
Level reverse
Counter clear
165