MSM80C154S/83C154S/85C154HVS

4.5.2.5Timer/counters 0/1 timer modes 4.5.2.5.1 Outline

The timer/counter 0 and 1 timer modes are set by combinations of M0 and M1 bit data in the timer mode register (TMOD 89H) shown in Table 4-11. The timer modes which can be set are 0, 1, 2, and 3.

Timer/counter 0 modes are specified by M0 and M1 of bits 0 and 1, and timer/counter 1 modes are specified by M0 and M1 of bits 4 and 5.

Table 4-11 Timer mode register (TMOD 89H)

 

 

TIMER COUNTER 1

 

 

TIMER COUNTER 0

 

Bit

7

6

5

4

3

2

1

0

Flag

GATE

C/T

M1

M0

GATE

C/T

M1

M0

 

 

 

 

 

 

 

 

 

Set

 

 

 

 

 

 

 

 

 

 

 

 

 

4.5.2.5.2 Mode 0

M1

M0

 

 

0

0

 

 

In mode 0, timer/counters 0 and 1 both become 13-bit timer/counters by the circuit connection shown in Figures 4-11 and 4-12. TL0 and TL1 in timer/counters 0 and 1 serve as the counter for the five lower bits, and TH0 and TH1 serve as the counter for the eight upper bits.

TF0 of TCON is set by the timer/counter 0 carry signal, and TF1 of TCON is set by the timer/ counter 1 carry signal. Note that the timer/counter 1 carry signal can also be used as the serial port transmission/reception clock.

Although the three upper bits of TL0 and TL1 are operative, they are invalid as signals.

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Sonic Alert msm85c154hvs, msm83c154s, msm80154s user manual Mode, Timer mode register Tmod 89H, Timer Counter