Operation Of Square Wave Output Initialization Function; Figure 7.8-1 Initialization Equivalent Circuit For Square Wave Output; Table 7.8-1 Square Wave Output Initialization Procedure (T1Cr Register) - Fujitsu F2MC-8L Series Hardware Manual

CHAPTER 7 8/16-BIT TIMER/COUNTER
7.8

Operation of Square Wave Output Initialization Function

The square wave output (TO) can be set to an arbitrary initial value with the timer 1
control register (T1CR).
Operation of Square Wave Output Initialization Function (Timer 1)
The square wave output can be set to an arbitrary initial value by software only when the timer
stops operation (T1CR: T1STR = "0").
Figure 7.8-1 shows the initialization equivalent circuit of the square wave controller.
initialization, follow the procedure in Table 7.8-1. Square wave output operation is performed as
illustrated in Figure 7.8-2.

Figure 7.8-1 Initialization Equivalent Circuit for Square Wave Output

T1STR
T1OS1
T1OS0
Write strobe signal

Table 7.8-1 Square Wave Output Initialization Procedure (T1CR Register)

Step
(1)
(2)
(3)
182
Level latch
D Q _ D Q
_
>
>
Q
Level latch
_
D Q D Q
>
>
Q
To set the square wave output pin (T0) to the "L" level, write "01
wave output control bits (T1CR: T10S1 and T10S0). To set the T0 pin to the "H"
level, write "10 " in the square wave output control bits.
B
Note:
Until "11 " is written to the bits, the value is held in the level latch, the T0 pin is
B
replaced in the output status and its output is undefined.
If "11 " is written to the square wave output control bits (T10S1 and T10S0), the
B
level (initial value) corresponding to the value in the level latch is output to the T0
pin. Do not perform the initial setting of pins (T10S1 and T10S0=11)
simultaneously with the counter start (T1STR=0 to 1).
When the counter start bit is set (T1STR=1), the counter starts operating.
The square wave output level is inverted each time the counter and data register
values match.
Output enable signal
Set output pin to "H."
(Set flip-flop for output.)
Q
_
Set output pin to "L."
Q
(Reset flip-flop for output.)
Setting and Operation
Flip-flop for
output
S
Q
P34/TO/INT0 pin
R
CK
Counter overflow signal
" to the square
B
For