MSM80C154S/83C154S/85C154HVS

4.5.2.5.5 Mode 3

M1

M0

 

 

1

1

 

 

In mode 3, timer/counter 0 TL0 and TH0 become independent 8-bit timer/counters by the circuit connection shown in Figure 4-17. Timer/counter 1 does not operate when mode 3 is set. The TL0 8-bit timer/counter is controlled in the same way as the regular timer/counter 0, TF0 being set if a carry signal is generated by TL0.

The TH0 8-bit timer/counter is controlled only by TR1, and the control only covers count starting and stopping. TF1 is set by a carry signal generated by TH0.

When timer/counter 0 is set to mode 3, timer/counter 1 can operate in modes 0, 1, or 2, and be used by the serial port clock. Control of timer/counter 1 count starting and stopping in this case is handled between operating mode and mode 3. If mode 3 is set, the timer/counter 1 counting operation is stopped.

XTAL 1

12

S3

DETECTOR TF0

T0 PIN DETECTOR (PORT 3.4)

C/ T

TR0

GATE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INT0 PIN

 

 

 

DATA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q

 

 

 

 

 

 

 

(PORT 3.2)

S5

 

LATCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

XTAL 1

 

12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TR1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q0------Q7

TL0

(8BITS)

 

DETECTOR

 

 

TF1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q0------Q7

TH0 C (8BITS)

Figure 4-17 Timer/counter 0 mode 3

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Sonic Alert msm85c154hvs Detector TF0 T0 PIN Detector Port TR0 Gate INT0 PIN Data, Latch Xtal, TL0 8BITS Detector TF1