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¡ Semiconductor

MSM82C53-2RS/GS/JS

• Select Counter (SC0, SC1):

Selection of set counter

• Read/Load (RL1, RL0):

Count value Reading/Loading format setting

• Mode (M2, M1, M0):

Operation waveform mode setting

0

¥

¥

0

M2

Set Contents

0

1

1

0

M1

1

0

1

0

M0

1

1

0

0

0

1

Mode 0 (Interrupt on Terminal Count)

Mode 1 (Programmable One-Shot)

Mode 2 (Rate Generator)

Mode 3 (Square Wave Generator)

Mode 4 (Software Triggered Strobe)

Mode 5 (Hardware Triggered Strobe)

¥ denotes "not specified".

• BCD:

Operation count mode setting

1

0

BCD

Binary Count (16-bit Binary)

BCD Count (4-decade Binary Coded Decimal)

Set Contents

After setting Read/Load, Mode, and BCD in each counter as outlined above, next set the desired

count value. (In some Modes, counting is started immediately after the count value has been

written). This count value setting must conform with the Read/Load format set in advance.

Note that the internal counters are reset to 0000H during control word setting. The counter

value (0000H) can’t be read.

If the two bytes (LSB and MSB) are written at this stage (RL0 and RL1 = 1,1), take note of the

following precaution.

Although the count values may be set in the three counters in any sequence after the control

word has been set in each counter, count values must be set consecutively in the LSB - MSB order

in any one counter.

0

1

1

0

SC1

1

0

1

0

SC0

Counter #0 Selection

Counter #1 Selection

Counter #2 Selection

Illegal Combination

Set Contents

0

1

1

0

RL1

Set Contents

1

0

1

0

RL0

Counter Latch Operation

Reading/Loading of Least Significant Byte (LSB)

Reading/Loading of Most Significant Byte (MSB)

Reading/Loading of LSB Followed by MSB