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NEC PD754144 User Manual

Page 127

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CHAPTER 6 PERIPHERAL HARDWARE FUNCTION

127

User’s Manual U10676EJ3V0UM

Figure 6-26. Format of Timer Counter Mode Register (Channel 0)

Note Be sure to clear bits 0 and 1 to 0 when setting data to TM0.

Caution After a reset, all bits of TM0 become "0", therefore when operating the timer it is necessary to

set the count pulse value first. Moreover, when any value other than the above is written to CP,

the count pulse set becomes 0 and TM0 does not operate as a timer.

7

6

5

4

3

2

1

0

PD754244: f

X

= 6.0 MHz

0

Note

0

Note

TM03

TM02

TM04

TM05

TM06

Address

TM0

FA0H

Symbol

Count pulse (CP) select bit

TM06

Count pulse (CP)

TM05

1

f

X

/2

10

(5.86 kHz)

0

f

X

/2

8

(23.4 kHz)

0

1

1

1

1

f

X

/2

4

(375 kHz)

1

Setting prohibited

f

X

/2

6

(93.8 kHz)

Other

TM04

0

1

0

1

PD754244: f

X

= 4.19 MHz

TM06

Count pulse (CP)

TM05

1

f

X

/2

10

(4.10 kHz)

0

f

X

/2

8

(16.4 kHz)

0

1

1

1

1

f

X

/2

4

(262 kHz)

1

Setting prohibited

f

X

/2

6

(65.5 kHz)

Other

TM04

0

1

0

1

TM03

Clears counter and IRQT0 flag when "1" is written. Starts count operation
if bit 2 is set to "1".

Timer start command bit

Operation mode

TM02

0

1

Stops (count value retained)

Count operation

Count operation

µ

µ

PD754144: f

CC

= 1.0 MHz

TM06

Count pulse (CP)

TM05

1

f

CC

/2

10

(977 Hz)

0

f

CC

/2

8

(3.91 kHz)

0

1

1

1

1

f

CC

/2

4

(62.5 kHz)

1

Setting prohibited

f

CC

/2

6

(15.6 kHz)

Other

TM04

0

1

0

1

µ

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